Question: 10 books are placed at random in a shelf. The probability that a pair of books will always be together is
Options:
(A) 1/6
(B) 1/9
(C) 1/5
(D) 1/6
(E) 1/3
Answer: 10 books can be rearranged in 10! ways consider the two books taken as a pair then number of favourable ways of getting these two books together is 9! 2!
Required probability = 1/5
The answer is (C).

Question: How much is 80% of 40 is greater than 4/5 of 20?
Options:
(A) 12
(B) 27
(C) 18
(D) 16
(E) 81
Answer: (80/100) * 40 (4/5) * 20
32 - 16 = 16
The answer is (D).

Question: A corporation triples its annual bonus to 50 of its employees. What percent E of the employees' new bonus is the increase?
Options:
(A) 50%
(B) 6623%
(C) 100%
(D) 200%
(E) 300%
Answer: E of the employees' new bonus is the increase Hence
The answer is (B).

Question: John makes $50 a week from his job. He earns a raise andnow makes $90 a week. What is the % increase?
Options:
(A) 15%
(B) 16.66%
(C) 17.8%
(D) 80%
(E) 21%
Answer:
Increase = (40/50)*100 = (4/5)*100 = 80%.
The answer is (D).