good ps

[vaivish]

If S is the sum of the reciprocal of a list of consecutive integers from 201 to 300, inclusive, which of the following about S is true?
(A) 0<S<1/3
(B) 1/4<S<1/3
(C) 1/3 < S < 1/2
(D) 1/2<S<2/3
(E) 2/3<S<1


OA is C

[lachlanc]

I'm going with (C)

Take the average reciprocal of 1/250 and multiply it by 100, you should get 10/25 or 0.4

Is that correct?

[malolakrupa]

Are the answer options correct , because the sum would be 1/201 + 1/202 ....1/300 , so the mimimum value is approxilately 0.005 and the last value is 0.0033 and I am not able to relate this to any of the answers.

[anju]

GMAT gurus pls. explain this

[Stuart@KaplanGMAT]

If S is the sum of the reciprocal of a list of consecutive integers from 201 to 300, inclusive, which of the following about S is true?
(A) 0<S<1/3
(B) 1/4<S<1/3
(C) 1/3 < S < 1/2
(D) 1/2<S<2/3
(E) 2/3<S<1


OA is C

We have 100 numbers on our list and we REALLY don't want to add them up. However, the answers are pretty big ranges (relative to our numbers, anyway), so let's look at the 2 extreme cases.

If every number had been 1/200, then the sum would be 100/200 = 1/2.

if every number had been 1/300, then the sum would be 100/300 = 1/3.

Our sum will be between the two extremes: choose (c), 1/3 < S < 1/2.