Below is the question from OG, a real tough one. I am totally clueless on this one. Please help me out. Thanks in advance
Beginning in January of last year, Carl made deposits
of $120 into his account on the 15th of each month
for several consecutive months and then made
withdrawals of $50 from the account on the 15th of
each of the remaining months of last year. There were
no other transactions in the account last year. If the
closing balance of Carl's account for May of last year
was $2,600, what was the range of the monthly
closing balances of Carl's account last year?
(1) Last year the closing balance of Carl's account
for April was less than $2,625.
(2) Last year the closing balance of Carl's account
for June was less than $2,675
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A very hard, above 700 DS question from OG 12
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xcusemeplz2009
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I think its D.gmat620 wrote:Below is the question from OG, a real tough one. I am totally clueless on this one. Please help me out. Thanks in advance
Beginning in January of last year, Carl made deposits
of $120 into his account on the 15th of each month
for several consecutive months and then made
withdrawals of $50 from the account on the 15th of
each of the remaining months of last year. There were
no other transactions in the account last year. If the
closing balance of Carl's account for May of last year
was $2,600, what was the range of the monthly
closing balances of Carl's account last year?
(1) Last year the closing balance of Carl's account
for April was less than $2,625.
(2) Last year the closing balance of Carl's account
for June was less than $2,675
To determine the range here we wil need to know exactly when the deposits stopped and withdrawls started. We already know May balance so we can find out balance of each month IF we know when the withdrawls stopped.
If in May there was a deposit, then april balance would be 2600 - 120 = 2480 and if there was a withdrawl then the balance would have been 2600 + 50 = 2650
If we take statement 1 then 2650 is ruled out. So there WAS a DEPOSIT in May.
Now for June if there was a deposit, the balance would be 2600 + 120 = 2720
If there was a withdrawl then June balance would be 2600 - 50 = 2550
If we take statement-2 then 2720 is ruled out so there was a WITHDRAWL in June.
Putting both statements together, we know that there was a deposit in May and withdrawl in June.
This information is enough to know all the remaining month balances. THerefore we can calculate the range.
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skprocks
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This thread does not seem to clarify the problem at hand.I will try to post an explannation that helps.First,things first.The most relevant part of this question is thatgmat620 wrote:Below is the question from OG, a real tough one. I am totally clueless on this one. Please help me out. Thanks in advance
Beginning in January of last year, Carl made deposits
of $120 into his account on the 15th of each month
for several consecutive months and then made
withdrawals of $50 from the account on the 15th of
each of the remaining months of last year. There were
no other transactions in the account last year. If the
closing balance of Carl's account for May of last year
was $2,600, what was the range of the monthly
closing balances of Carl's account last year?
(1) Last year the closing balance of Carl's account
for April was less than $2,625.
(2) Last year the closing balance of Carl's account
for June was less than $2,675
once withdrawal starts it continues for the rest of the year.And Deposits started prior to the withdrawals.Now,Look at the Statements.
Stmt1: Balance in April is < 2625. Its already known that the balance in May was 2600.5 consecutive deposits of 120 make just 600.
So, Brought Forward/Initial amount in Jan prior to any deposits was 2000.Since May was 2600,so April was also a deposit month.
As had may been withdrawal the amount in april shall be 2650 for May to be 2600,as withdrawals are in 50 denominations.
Thus April was a month when deposit was made.But this stmt gives no clue about when withdrawals began. INSUFFICIENT
Stm2: June balance was < 2675.Had june been a deposit month its balance wud be 2600+120=2720.But this stmt indicates otherwise,
so withdrawals began in June and continued till December.Now the fact indicated by this statement is just that withdrwals began in June.
Does not give sufficient info to assume Jan initial balance as 2000 et al.INSUFFICIENT
Combining Stmt1 and Stmt2 we get that Deposits continued till May and Withdrawals began in June.June onwards balance continuously falls
by50 each month.This gives the balance at the end of each month,Hence its possible to determine Range= Max- Min balance.
Jan->2120,2240,2360,2480,2600,2550,2500,2450,2400,2350,2300,2250.
Range = 2600-2120=480
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May = 2600.Beginning in January of last year, Carl made deposits
of $120 into his account on the 15th of each month
for several consecutive months and then made
withdrawals of $50 from the account on the 15th of
each of the remaining months of last year. There were
no other transactions in the account last year. If the
closing balance of Carl's account for May of last year
was $2,600, what was the range of the monthly
closing balances of Carl's account last year?
(1) Last year the closing balance of Carl's account for April was less than $2,625.
(2) Last year the closing balance of Carl's account for June was less than $2,675.
Statement 1: Last year the closing balance of Carl's account
for April was less than $2,625.
If 120 was deposited in May, then April = 2600-120 = 2480.
If 50 was withdrawn in May, then April = 2600+50 = 2650.
Since April < 2625, we know that a deposit of 120 was made in May, implying that 120 was deposited every month January through at least May.
Thus, we can determine the balance of every month January - April:
April = 2480, March = 2480-120 = 2360, etc.
No information about June - December.
Insufficient.
Statement 2: Last year the closing balance of Carl's account
for June was less than $2,675.
If 120 was deposited in June, then June = 2600+120 = 2720.
If 50 was withdrawn in June, then June = 2600-50 = 2550.
Since June < 2675, we know that a withdrawal of 50 was made in June, implying that 50 was withdrawn every month June - December.
Thus, we can determine the balance of every month June - December:
June = 2550, July = 2550-50 = 2500, etc.
No information about January - April.
Insufficient.
Statements 1 and 2 combined:
Statement 1 tells us the closing balances January - April.
The question stem tells us the closing balance in May.
Statement 2 tells us the closing balances June - December.
Combining the information above, we can determine the closing balance of every month and determine the range for the whole year.
Sufficient.
The correct answer is C.
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Given :Beginning in January of last year, Carl made deposits of $120 into his account on the 15th of each month for several consecutive months and then made withdrawals of $50 from the account on the 15th of each of the remaining months of last year. There were no other transactions in the account last year. if the closing balance of Carl's account for May of last year was $2,600, what was the range of the monthly closing balances of Carl's account last year?
(1) Last year the closing balance of Carl's account for April was less than $2,625.
(2) Last year the closing balance of Carl's account for June was less than $2,675.
Jan
Feb
Mar
Apr
May - $2600
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Statement 1: April < 2625
Since either $50 withdrawl or $120 deposit is possible so for withdraw of $50 in May, April must have been $2600+50 = 2650 for a deposit of $50 which is not true as per statement 1 i.e. Deposit of $120 must have happened in all the months before MAY till MAY
Jan - $2120
Feb - $2240
Mar - $2360
Apr - $2480
May - $2600
Jun
Jul
Aug
Sep
Oct
Nov
Dec
It gives us the amount from Jan to may but not for months later so
NOT SUFFICIENT
Statement 2: June < 2675
Since either $50 withdrawl or $120 deposit is possible so for withdraw of $50 in May, June must have been $2600+120 = $2720 for a deposit of $120 which is not true as per statement 2 i.e. Withdrawl of $50 must have happened in all the months After MAY
Jan
Feb
Mar
Apr
May - $2600
Jun - $2550
Jul - $2500
Aug - $2450
Sep - $2400
Oct - $2350
Nov - $2300
Dec - $2250
It gives us the amount from May to Dec but not for months before MAY so
NOT SUFFICIENT
Combining the two statements
Jan - $2120
Feb - $2240
Mar - $2360
Apr - $2480
May - $2600
Jun - $2550
Jul - $2500
Aug - $2450
Sep - $2400
Oct - $2350
Nov - $2300
Dec - $2250
SUFFICIENT
Answer: option C
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Brent@GMATPrepNow
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Target question: What was the range of the monthly closing balances of Carl's account last year?gmat620 wrote:Below is the question from OG, a real tough one. I am totally clueless on this one. Please help me out. Thanks in advance
Beginning in January of last year, Carl made deposits
of $120 into his account on the 15th of each month
for several consecutive months and then made
withdrawals of $50 from the account on the 15th of
each of the remaining months of last year. There were
no other transactions in the account last year. If the
closing balance of Carl's account for May of last year
was $2,600, what was the range of the monthly
closing balances of Carl's account last year?
(1) Last year the closing balance of Carl's account
for April was less than $2,625.
(2) Last year the closing balance of Carl's account
for June was less than $2,675
Given: The closing balance of Carl's account for May of last year was $2,600
IMPORTANT: To answer the target question we need only determine which month Carl STARTED withdrawing money.
For example, if he started withdrawing money on March 15, we could use the fact that he had $2600 at the end of May to determine how much he had in the bank every month of the year, and thus determine the range of closing balances.
Notice that, since this is a Data Sufficiency, we need not calculate the actual range. We need only determine which month the deposits stopped and the withdrawals started.
So, we can rephrase our target question as . . .
REPHRASED target question: In which month did Carl start withdrawing $50?
Statement 1: Last year the closing balance of Carl's account for April was less than $2,625
Let's examine two cases:
case a: In May, Carl DEPOSITED $120. So, balance at end of April = $2600 - $120 = $2480. This is possible, since we're told that the balance is less than $2625
case b: In May, Carl WITHDREW $50. So, balance at end of April = $2600 + $50 = $2650. This is NOT possible, since we're told that the balance is less than $2625
So, Carl definitely deposited $120 in May (and deposited $120 in April, March, Feb, and Jan).
However, we don't know the first month that Carl started withdrawing $50
Since we cannot answer the REPHRASED target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: Last year the closing balance of Carl's account for June was less than $2,675.
Let's examine two cases:
case a: In June, Carl DEPOSITED $120. So, balance at end of June = $2600 + $120 = $2720. This is NOT possible, since we're told that the balance is less than $2675
case b: In June, Carl WITHDREW $50. So, balance at end of June = $2600 - $50 = $2550. This is possible, since we're told that the balance is less than $2675
So, Carl definitely withdrew $50 in June, which means he also withdrew $50 in July, August, Sept, etc. However, we don't know the FIRST month that Carl started withdrawing $50
Since we cannot answer the REPHRASED target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined
Statement 1 tells us that Carl deposited $120 in May.
Statement 2 tells us that Carl withdrew $50 in June.
So, June was the first month that Carl started withdrawing $50
Since we can answer the REPHRASED target question with certainty, the combined statements are SUFFICIENT
Answer = C
Cheers,
Brent
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Amrabdelnaby
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I think the logic behind this question is very simple although it appears from the first glance to be terribly difficult.
basically statement 1 tells us what happened from jan to may (deposits) but doesn't tell us what happened afterwards.
and statement two tells us what happened from june untill the end of the year.
hence statement one and two combined give us an insight about the withdrawals and deposits hence we know how much he had left in the account by the end of the year and how much he had in the beginning and hence we can find the range.
I have noticed that all data sufficiency questions use this logic, one statement pushes the answer choice in one direction; sometimes it's enough and sometimes it needs another statement to corner the answer choice in one place. Or both answer choices fail to yield one possible result
basically statement 1 tells us what happened from jan to may (deposits) but doesn't tell us what happened afterwards.
and statement two tells us what happened from june untill the end of the year.
hence statement one and two combined give us an insight about the withdrawals and deposits hence we know how much he had left in the account by the end of the year and how much he had in the beginning and hence we can find the range.
I have noticed that all data sufficiency questions use this logic, one statement pushes the answer choice in one direction; sometimes it's enough and sometimes it needs another statement to corner the answer choice in one place. Or both answer choices fail to yield one possible result
GMATGuruNY wrote:May = 2600.Beginning in January of last year, Carl made deposits
of $120 into his account on the 15th of each month
for several consecutive months and then made
withdrawals of $50 from the account on the 15th of
each of the remaining months of last year. There were
no other transactions in the account last year. If the
closing balance of Carl's account for May of last year
was $2,600, what was the range of the monthly
closing balances of Carl's account last year?
(1) Last year the closing balance of Carl's account for April was less than $2,625.
(2) Last year the closing balance of Carl's account for June was less than $2,675.
Statement 1: Last year the closing balance of Carl's account
for April was less than $2,625.
If 120 was deposited in May, then April = 2600-120 = 2480.
If 50 was withdrawn in May, then April = 2600+50 = 2650.
Since April < 2625, we know that a deposit of 120 was made in May, implying that 120 was deposited every month January through at least May.
Thus, we can determine the balance of every month January - April:
April = 2480, March = 2480-120 = 2360, etc.
No information about June - December.
Insufficient.
Statement 2: Last year the closing balance of Carl's account
for June was less than $2,675.
If 120 was deposited in June, then June = 2600+120 = 2720.
If 50 was withdrawn in June, then June = 2600-50 = 2550.
Since June < 2675, we know that a withdrawal of 50 was made in June, implying that 50 was withdrawn every month June - December.
Thus, we can determine the balance of every month June - December:
June = 2550, July = 2550-50 = 2500, etc.
No information about January - April.
Insufficient.
Statements 1 and 2 combined:
Statement 1 tells us the closing balances January - April.
The question stem tells us the closing balance in May.
Statement 2 tells us the closing balances June - December.
Combining the information above, we can determine the closing balance of every month and determine the range for the whole year.
Sufficient.
The correct answer is C.
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Matt@VeritasPrep
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The wording is pretty boring and dry: I think the idea is to test your ability to focus on very literal descriptions of financial transactions, something that many/most MBAs will have to deal with during their classes and afterwards. But it isn't all that difficult or convoluted if you're able to stay awake while reading it (easier said than done!Amrabdelnaby wrote:I think the logic behind this question is very simple although it appears from the first glance to be terribly difficult.
)
