Find a positive number which when increased by 17 is equal to 60 times the reciprocal of the number.

A.    3   
B.    10
C.    17   
D.    20
Ans: A

Explanation:

Let the number be x.
Then, x + 17 =    60/6
x2 + 17x - 60 = 0
(x + 20)(x - 3) = 0
x = 3.