Reasoning: This alternating addition series begins with 3; then 1 is added to give 4; then 3 is added to give 7; then 1 is added, and so on.
Ans: (A)
Question: Look at this series: 3, 4, 7, 8, 11, 12, ... What number should come next?
Options:
(A) 15
(B) 14
(C) 17
(D) 12
(E) 19
Rationale: Here, l = 6 and m = 18
Therefore, first number = l/m x 100% of second number = 6/18 x 100% of second number = 33 1/3% of second number
The answer: (D)
Question: If the given two numbers are respectively 6% and 18% of a third number, then what percentage is the first of the second ?
Options:
(A) 20%
(B) 25%
(C) 18%
(D) 33 1/3%
(E) none of these
Reasoning: 70 + 50 = 120 * 5/18 = 100/3 mps
D = 150 + 100 = 250 m
T = 250 * 3/100 = 15/2 = 7 1/2 sec
Ans: (D)
Question: Two trains are moving at 50 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?
Options:
(A) 7 1/6 sec
(B) 7 3/2 sec
(C) 7 1/7 sec
(D) 7 1/2 sec
(E) 3 3/2 sec
Rationale: Let the boys are X, then girls are 7X, total = X+7X = 8X
So it should be multiple of 8, 30 is not a multiple of 8.
The answer: (C)
Question: The no. of girls in a class are seven times the no. of boys, which value cannever be the of total students?
Options:
(A) 10
(B) 25
(C) 30
(D) 45
(E) 50
Reasoning: According to the information in the question the maximum range would be between 510 and 780(270). The minimum range would be the greatest range for any one individual, which is listed in the problem as 130. So the difference between these would be 270-130 or 140.
Ans: (D)
Question: Three people took GMAT practice tests in which the minimum and maximum possible scores are 200 and 800, respectively. They each took a test 3 times, and no one scored below 510 or over 780. If the individual ranges of the three people's scores in those 3 practice tests were 20, 90 and 130, what is the difference between the maximum and minimum possible ranges of all their scores put together.
Options:
(A) 70
(B) 80
(C) 90
(D) 140
(E) 170
Reasoning: 4/9 P = (P*R*R)/100
R = 20/3 = 6 2/3%
Ans: (A)
Question: The simple interest on a sum of money is 4/9 of the principal and the number of years is equal to the rate percent. Find the rate and the time?
Options:
(A) 6 2/3%
(B) 6 2/8%
(C) 6 9/3%
(D) 6 2/3%
(E) 6 2/1%