q: A train of 24 carriages, each of 60 meters length, when an engine also of 60 meters length is running at a speed of 60 kmph. In what time will the train cross a bridge 1.5 km long?
Options:
(A) 6
(B) 3
(C) 4
(D) 9
(E) 2
a: OK... D = 25 * 60 + 1500 = 3000 m
T = 3000/60 * 18/5 = 180 sec = 3 mins
The answer is (B).

q: Look at this series: 53, 53, 46, 46, 39, 39, ... What number should come next?
Options:
(A) A) 12
(B) B) 14
(C) C) 27
(D) D) 32
(E) E) 86
a: OK... In this series, each number is repeated, then 7 is subtracted to arrive at the next number.
The answer is (D).

q: How many positive integers less than 500 can be formed using the numbers 1,2,3,and 5 for digits, each digit being used only once.
Options:
(A) 22
(B) 34
(C) 73
(D) 26
(E) 11
a:
OK... Single digit numbers = 4
Double digit numbers = 4 x 3 = 12
Three digit numbers = 3 x 3 x 2 x 1 = 18
Total = 34
The answer is (B).