What percent is 120 of 60?
Options:
(A) 133 1/3 %
(B) 134 1/3 %
(C) 200 %
(D) 140 1/3 %
(E) 143 1/3 %

120/60 = 2/1
2 100 = 200 % So the answer is: (C).

Which one of the following is not a prime number?
Options:
(A) 51
(B) 61
(C) 71
(D) 82
(E) 91

91 is divisible by 7. So, it is not a prime number. So the answer is: (E).

Find the wrong number below mentioned series
5,24,60,120,210,340
Options:
(A) 340
(B) 210
(C) 5
(D) 60
(E) none

5 is the only prime number or odd number in the series. So the answer is: (C).

A can do a piece of work in 3 hours; B and C together can do it in 2 hours, which A and B together can do it in 2 hours. How long will C alone take to do it?
Options:
(A) 2hours
(B) 5hours
(C) 6hours
(D) 4hours
(E) 3hours
A's 1 hour work = 1/3;
(B + C)'s 1 hour work = 1/2;
(A + B)'s 1 hour work = 1/2
(A + B + C)'s 1 hour work = (1/3 + 1/2) = 5/6
C's 1 hour work = (5/6 - 1/2) = 1/3
C alone will take 3 hours to do the work. So the answer is: (E).