OG 64

[Uri]

If d denotes a decimal, is d ≥ 0.5 ?
(1) When d is rounded to the nearest tenth, the result is 0.5.
(2) When d is rounded to the nearest integer, the result is 1.

The official answer is B. The explanation given is as below:

(1) In this case, for example, the value of d could range from the decimal 0.45 to 0.54. Some of these, such as 0.51 or 0.52, are greater than or equal to 0.5, and others, such as 0.47 or 0.48, are less than 0.5; NOT sufficient.

(2) When the result of rounding d to the nearest integer is 1, d could range in value from the decimal 0.50 to 1.49, which are greater than or equal to 0.5; SUFFICIENT.

I do not think that B is sufficient. Suppose d is 0.25. If rounded to the nearest integer, it will become 1. And if d=0.65, then also it will become 1 when rounded to the nearest integer.

Or, should I take 0 (zero) as the nearest integer to 0.25? Could you please point out the mistake I am probably making?

[Frankenstein]

should I take 0 (zero) as the nearest integer to 0.25? Could you please point out the mistake I am probably making?

Yes.. If the decimal is less than 0.5, when rounded the number will be the preceding integer else it will be the next integer.
0.49 -> rounded becomes 0

[Geva@EconomistGMAT]

If d denotes a decimal, is d ≥ 0.5 ?
(1) When d is rounded to the nearest tenth, the result is 0.5.
(2) When d is rounded to the nearest integer, the result is 1.

The official answer is B. The explanation given is as below:

(1) In this case, for example, the value of d could range from the decimal 0.45 to 0.54. Some of these, such as 0.51 or 0.52, are greater than or equal to 0.5, and others, such as 0.47 or 0.48, are less than 0.5; NOT sufficient.

(2) When the result of rounding d to the nearest integer is 1, d could range in value from the decimal 0.50 to 1.49, which are greater than or equal to 0.5; SUFFICIENT.

I do not think that B is sufficient. Suppose d is 0.25. If rounded to the nearest integer, it will become 1. And if d=0.65, then also it will become 1 when rounded to the nearest integer.

Or, should I take 0 (zero) as the nearest integer to 0.25? Could you please point out the mistake I am probably making?

1) Zero is an integer. That's probably the misconception you suffering from

2) When rounding to the nearest nth digit, the process is as follows:

a. Go to the digit you're rounding to. In our case, the units' digit of 0.25 is '0'.

b. Look at the next digit to the right.

If the next digit is 0-4, round down: Erase all digits from the right digit onwards, inclusive. Leave the nth digit as is.
If the next digit is 5-9, round up: Erase all digits from the right digit onwards, inclusive. Add 1 to the nth digit.

thus, for 0.25 rounded to the nearest unit, we go to the units digits '0', and look at the next digit on the right, which is 2. Since 2 is in the 0-4 range, we round down: delete the 2 and the 5, leaving 0.0.

For 0.65 rounded to the nearest unit, we go to the units digit '0' and look at the next digit on the right, which is 6. Since 6 is in the 5-9 range, we round up: delete the 6 and the 5, and add one to the 0 to get 1.

Another example: what is 4.356 rounded to the nearest tenth?
Go to the tenths digit "3", and look at the next digit to the right: a "5".
Since 5 is in the 5-9 range, round up: delete the 5 and the 6, and add 1 to the "3" to get 4.4
.

[sandysai]

I have a doubt regarding second choice. In case B "When d is rounded to the nearest integer, the result is 1."

Eg : i consider example 0.49 ( rounded to nearest interger is 1 right ) , But in reality 0.49 < 0.5 .On other hand if i consider 0.51 or above the solution is satisfied . so how is B sufficient. what am i missing here.

please assist .

Thanks
Sandhya

[sandysai]

Hi All,
I have a doubt regarding second choice. In case B "When d is rounded to the nearest integer, the result is 1."

Eg : i consider example 0.49 ( rounded to nearest interger is 1 right ) , But in reality 0.49 < 0.5 .On other hand if i consider 0.51 or above the solution is satisfied . so how is B sufficient. what am i missing here.

please assist .

Thanks
Sandhya

[[email protected]]

Hi Sandhya, just wondering if you got a response on your question. 0.49 would also round up to 1.

[[email protected]]

HI sakshi.m91,

Since this series of posts goes back a couple of years (2011-2012), my guess is that most of the posters are gone. I can answer your question though.

0.49, when rounded to the nearest integer, gives us 0 (not 1). If you "round up" to the nearest integer, you'd get 1. The information in Fact 2 does NOT tell us to round up though, it tells us that when we round to the nearest integer, we get 1.

The range of values, that when rounded to the nearest integer = 1, is...

0.50 to 1.49, inclusive.

Since the question asks if D is >= to 0.5, the information in Fact 2 would gives us a consistent answer to the question: ALWAYS YES. Thus, Fact 2 is SUFFICIENT.

GMAT assassins aren't born, they're made,
Rich

[[email protected]]

ok, so whenever we are looking to round, we only look at the immediate number on the right as opposed to the entire string. And therefore,the thought process that:

1) 0.49 rounded to the nearest tenth (which would be 0.5)
2) which is further rounded to the nearest integer (would be 1)

is not the right approach to rounding decimals?

[[email protected]]

Hi sakshi.m91,

When rounding, you have to look at the digit to the immediate right of what you're rounding to:

If the digit is...
0-4, then round down
5-9, then round up

eg. 2.3592

Rounded to the nearest integer, we have 2 (because "3" tells us to round down)
Rounded to the nearest tenth, we have 2.4 (because "5" tells us to round up)
Rounded to the nearest hundredth, we have 2.36 (because "9" tells us to round up)
Rounded to the nearest thousandth, we have 2.359 (because "2" tells us to round down)

So, 0.49 rounded to the nearest tenth would be 0.5 (because the "9" tells us to round up)
0.49 rounded to the nearest integer would be 0 (because the "4" tells us to round down)

GMAT assassins aren't born, they're made,
Rich

[Scott@TargetTestPrep]

If d denotes a decimal, is d ≥ 0.5 ?
(1) When d is rounded to the nearest tenth, the result is 0.5.
(2) When d is rounded to the nearest integer, the result is 1.

We are given that d is a decimal, and we need to determine whether d is greater than or equal to 0.5.

Statement One Alone:

When d is rounded to the nearest tenth, the result is 0.5.

Using the information in statement one, we can get a multitude of values for d.

For example, d can be 0.51, and 0.51 is greater than or equal to 0.5.

In another case, d can be 0.49, but 0.49 is not greater than or equal to 0.5.

Statement one is not sufficient to answer the question. We can eliminate answer choices A and D.

Statement Two Alone:

When d is rounded to the nearest integer, the result is 1.

In order for d to be rounded to 1 (when rounded to the nearest integer), the value of d must be at least 0.5. Statement two is sufficient to answer the question.

Answer: B