A can do a job in 18 days and B can do it in 24 days. A and B working together will finish twice the amount of work in days?
Options:
(A) 22 1/6
(B) 22 1/2
(C) 20 4/7
(D) 22 1/9
(E) 22 1/1

1/18 + 1/24 = 7/72
72/7 = 72/7 *2 = 20 4/7 days So the answer is: (C).

An analyst will recommend a combination of 4 industrial stocks, 3 transportation stocks, and 4 utility stocks. If the analyst can choose from 5 industrial stocks, 4 transportation stocks, and 5 utility stocks, how many different combinations of 11 stocks are possible?
Options:
(A) 12
(B) 19
(C) 60
(D) 100
(E) 720

5C4 * 4C3 * 5C4 = 5*4*5 = 100. So the answer is: (D).

What approximate value should come in place of question mark (?) in the following equation
287.532 + 1894.029 757.48 = 443.095 + ?
Options:
(A) 870
(B) 790
(C) 680
(D) 770
(E) 890

? = 285 + 1895 755 745 or, ? = 680 So the answer is: (C).

Two persons A and B can complete a piece of work in 40 days and 60 days respectively. If they work together, what part of the work will be completed in 6 days?
Options:
(A) 1/8
(B) 1/3
(C) 1/6
(D) 1/2
(E) 1/4
A's one day's work = 1/40
B's one day's work = 1/60
(A + B)'s one day's work = 1/40 + 1/60 = 1/24
The part of the work completed in 6 days = 6 (1/24) = 1/4. So the answer is: (E).