Search found 85 matches
Probalility
The governor has decided to pardon one of the three prisoners (A, B, C) who are on death row and informs the prison warden about his decision. Prisoner A asks the warden which prisoner will be pardoned and the warden informs him that B is to be executed. What is the updated probability of A being pa...
- by Anindya Madhudor
Sun Sep 08, 2013 7:32 am- Forum: Problem Solving
- Topic: Probalility
- Replies: 2
- Views: 1107
In 4 days, A completes 4/24 part of the whole work. Remaining work is 20/24 after 4 days. When B joins after 4 days, A and B together do (1/24 + 1/32)*4 = 7/24. So remaining work after 8 days is (20/24 -7/24) =13/24. When C joins after another 4 days, A, B and C can do (1/24 + 1/32+ 1/48) = 3/32 in ...
- by Anindya Madhudor
Sat Sep 07, 2013 8:32 am- Forum: Problem Solving
- Topic: A, B and C working alone can complete a work in 24
- Replies: 4
- Views: 1818
Combination problem
If n balls are placed at random into n cells, find the probability that exactly one cell remains empty.
A. n/2n!
B. n!/n^n
C. (2n)!/n^n
D. (nC2)* n!/n^n
E. (nC2)* (2n)!/n^n
OA: D
- by Anindya Madhudor
Sat Sep 07, 2013 7:46 am- Forum: Problem Solving
- Topic: Combination problem
- Replies: 3
- Views: 2495
legislature seems to talk at great length
The legislature seems to talk at great length about reform but to do almost nothing to achieve that. (A) to do almost nothing to achieve that (B) to do almost nothing achieving such (C) to do almost nothing to achieve it (D) doing almost nothing in achieving any (E) doing almost nothing to achieve t...
- by Anindya Madhudor
Wed Dec 19, 2012 7:39 am- Forum: Sentence Correction
- Topic: legislature seems to talk at great length
- Replies: 7
- Views: 1599
Statement I:
Possible solutions are a= b or a=-b. So, ab= a^2 or (-a^2). We cannot definitely answer the question. Not sufficient.
Statement II:
a^3 = b^3 means a=b. So, ab=a^2. Sufficient.
- by Anindya Madhudor
Tue Dec 18, 2012 10:41 pm- Forum: Data Sufficiency
- Topic: Does ab = a^2
- Replies: 2
- Views: 1023
grammatical rule
Can someone please explain the grammatical rule in solving the following question. The guiding principles of the tax plan released by the Treasury department could have even a greater significance for the economy than the particulars of the plan. a. even a greater significance for the economy than b...
- by Anindya Madhudor
Tue Dec 18, 2012 10:30 pm- Forum: Sentence Correction
- Topic: grammatical rule
- Replies: 3
- Views: 1668
Statement I:
If R>4, e.g., 5 or 6, S <0 to satisfy the equation R + S =4. This is true for all values of R>4. So, sufficient.
Statement II:
S could be -3 or 3. We cannot definitely answer whether S<0 or not. Not sufficient.
- by Anindya Madhudor
Tue Dec 18, 2012 10:16 am- Forum: Data Sufficiency
- Topic: Inequality DS.
- Replies: 3
- Views: 906
You need to find the pattern in the exponential. When the last digit of any number is 3, you have the pattern 3, 9, 7, 1 for powers of 1, 2 ,3,4. This pattern repeats. So, it will be same for powers of 5, 6, 7, 9. You divide the power by 4 and find the remainder. 43 divided by 4 leaves 3 as remainde...
- by Anindya Madhudor
Tue Dec 18, 2012 7:45 am- Forum: Problem Solving
- Topic: unit digit problem
- Replies: 3
- Views: 1224
- by Anindya Madhudor
Tue Dec 18, 2012 7:33 am- Forum: Data Sufficiency
- Topic: Inequality DS.
- Replies: 3
- Views: 906
Statement I: 22=2*11 15z= 3*5*z 15 and 22 do not have any common factors. So, if 22 is a factor of 15Z, 22 has to be a factor of z. Sufficient. Statement II: Same logic as before. In this case, 22 and 16 have 2 as a common factor. So, 22 may or may not be a factor of z. For example, if z=11, then 2...
- by Anindya Madhudor
Tue Dec 18, 2012 7:23 am- Forum: Data Sufficiency
- Topic: Number Ds
- Replies: 2
- Views: 995
Let's analyze the first part of the given expression. 3^(4n + 2) can only have 9 as remainder when divided by 10. Pick any value to n to test this. The value of n is immaterial in this case. To evaluate the whole expression, we just need to know the value of m. If we know the value of m, we can add ...
- by Anindya Madhudor
Sun Dec 16, 2012 3:45 am- Forum: Data Sufficiency
- Topic: If n and m are positive integers , what is the reminder
- Replies: 4
- Views: 7001
Speed Distance
Train A leaves New York for Boston at 3 PM and travels at the constant speed of 100 mph. An hour later, it passes Train B, which is making the trip from Boston to New York at a constant speed. If Train B left Boston at 3:50 PM and if the combined travel time of the two trains is 2 hours, what time d...
- by Anindya Madhudor
Sat Dec 15, 2012 1:37 pm- Forum: Problem Solving
- Topic: Speed Distance
- Replies: 1
- Views: 850
Distance Speed
Stephanie, Regine, and Brian ran a 20 mile race. Stephanie and Regine's combined times exceeded Brian's time by exactly 2 hours. If nobody ran faster than 8 miles per hour, who could have won the race? i. Stephanie ii. Regine iii. Brian a. i only b. ii only c. iii only d. i or ii only e. i or ii or ...
- by Anindya Madhudor
Sat Dec 15, 2012 1:29 pm- Forum: Problem Solving
- Topic: Distance Speed
- Replies: 2
- Views: 1064
First, let's look at the given expression and try to express this as a product of prime factors. 450 y = n^3 => 5^2 * 3^2 * 2 y =n^3 Since, n is an integer, let us find some of the possible values of y. Y could be 5 * 3 * 2^2, in which case n= 5* 3 *2. Y could be 5^4 * 3 * 2^2, in which case n= 5^2 ...
- by Anindya Madhudor
Fri Dec 14, 2012 11:34 am- Forum: Problem Solving
- Topic: If n and y are positive integers and 450y=n^3, which of
- Replies: 3
- Views: 1263
- by Anindya Madhudor
Fri Dec 14, 2012 11:09 am- Forum: Problem Solving
- Topic: Probability
- Replies: 2
- Views: 991