Rationale: (10/100)Workers = 16 = > number of workers = 160
(10/100)*Workers = x+16 = > x = 16
The answer: (A)
Question: In an office, 10 percent of the workers have at least 5 years of service, and a total of 16 workers have at least 10 years of service. If 90 percent of the workers have fewer than 10 years of service, how many of the workers have at least 5 but fewer than 10 years of service?
Options:
(A) 16
(B) 64
(C) 50
(D) 144
(E) 160

Rationale: Clearly, 252 = 2 x 2 x 3 x 3 x 7.
The answer: (A)
Question: 252 can be expressed as a product of primes as:
Options:
(A) 2 x 2 x 3 x 3 x 7
(B) 2 x 2 x 3 x 3 x 8
(C) 2 x 2 x 3 x 3 x 6
(D) 2 x 2 x 3 x 3 x 1
(E) 2 x 2 x 3 x 3 x 2

Rationale: 9 = 5 blue balls + 20/ 5
The answer: (B)
Question: There are 25 balls in a jar. You take out 5 blue balls without putting them back inside, and now the probability of pulling out a blue ball is 1/5. How many blue balls were there in the beginning?
Options:
(A) 12.
(B) 9.
(C) 8.
(D) 7.
(E) 6.