If the ratio of boys to girls in a class is B and the ratio of girls to boys is G; then 3 (B + G) is ?
Options:
(A) Equal to 3
(B) Less than 3
(C) More than 3
(D) Less than 1/3
(E) none of these

Let number of boys = x
Let number of girls = y
Therefore x/y = B and y/x = G
3(B + G) = 3[(x/y) + (y/x)] = 3[(x2 + y2)/xy] > 3 So the answer is: (C).

Two trains are traveling on parallel tracks in the same direction. The faster train travels at 120 miles per hour, while the slower train travels at 100 miles per hour. At 2 o'clock the faster train is 10 miles behind the slower one. How far apart are the two trains at 6 o'clock?
Options:
(A) 60 miles
(B) 80 miles
(C) 110 miles
(D) 120 miles
(E) 400 miles

Answer = C. 110 miles
Relational speed = 120 - 100 = 20 miles per hour
In 4 hours, difference = 20 * 4 = 120 miles
Fast train trailing 10 miles, so effective difference = 120 - 10 = 110 miles So the answer is: (C).

John's grade was 80th percentile of the 100 grades for his class. Of the 60 grades from another class, 20 were higher than John's, and the rest were lower. If no other grade was the same as John's grade, then John's grade was what percentile of the grades of the two classes of two classes combined?
Options:
(A) 72nd
(B) 75th
(C) 83rd
(D) 85th
(E) 94th

72nd/75th/83rd/85th/94th So the answer is: (B).

Fill in the blank with the correct number in this number series: 20, 65, 27, 61, __, 57, 41, ?
Options:
(A) 34
(B) 35
(C) 38
(D) 25
(E) 56
This is a simple alternating subtraction and addition series; The first series begins with 20 and adds 7; the second begins with 65 and subtracts 4, and so on. So the answer is: (A).