hi guys,

as mentioned in other posts i made around here, I am currently doing the BEAT THE GMAT 60 DAYS ONLINE COURSE. However, the correct answers in the excel sheet differ from the correct answers in the 13 th edition of the Official Guidefor Gmat Review (OG -13).

Let me give you 2 examples, both are from PROBLEM SOLVIING set, of the very first test (on page 20).

1. First example: Quesition nr. 2:

The average (arithmetic mean) of the integers from 200 to 400, inclusive, is how much greater than the average of the integers from 50 to 100, inclusive?
(A) 150
(B) 175
(C) 200
(D) 225
(E) 300

The correct answer here is obviously D (300 - 75 = 225). This is also the correct answer given in the ANSWER KEY on page 45. However, when I write this in the excel file, it shows my answer (D) as incorrect and marks C as the correct letter.

Second example: Question 4:

Among a group of 2,500 people, 35 percent invest in municipal bonds, 18 percent invest in oil stocks, and 7 percent invest in both municipal bonds and oil stocks. If 1 person is to be randomly selected from the 2,500 people, what is the probability that the person selected will be one who invests in municipal bonds but NOT in oil stocks?

(A) 9/50

(B) 7/25


(C) 7/20

(D) 21/50

(E) 27/50

The correct answer in the Answer key is B. The chart, though, marks it as C.

I realize how helpful tool the excel chart is, but still do not know how to overcome this problem. Help is really appreciated.

Cheers