a2zinterviews

16.	Worker A takes 8 hours to do a job. Worker B takes 10 hours to do the same job. How long should it take both A and B, working together but indepently, to do the same job?
	A.  2x4/9
	B.  4x4/9
	C.  5x4/9
	D.  4x2/9

Solution

A's 1 day's work = 1/8 B's 1 day's work = 1/10 (A+B)'s 1 day's work = (1/8 + 1/10) = 9/40. Both A and B will finish the work in = 40 / 9 ‹=›4×4/9

17.	A and B together can complete a work in 12 days. A alone can complete it in 20 days. If B does the work only for half a day daily, then in how many days A and B together will complete the work?
	A.  10 days
	B.  11 days
	C.  15 days
	D.  20 days

Solution

B's 1 day's work = (1/12 - 1/20) = 2/60 = 1/30 Now, (A+B)'s 1 day's work (1/12 +1/60) = 4/60 = 1/15. So A and B together will complete the work in 15 days.

18.	A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is
	A.  1/4
	B.  1/10
	C.  7/15
	D.  8/15

Solution

A's 1 day's work = 1/15 B's 1 day's work = 1/20 (A+B)'s 1 day's work = (1/15 + 1/20) = 7/60. (A+B)'s 4 day's work = (7/60x4) = 7/15. Remaining Work = (1–7/15) = 8/15.

19.	A and B together can complete a piece of work in 4 days. If A alone can complete the same work in 12 days. In how many days can be alone complete that work?
	A.  1/3 days
	B.  1/6 days
	C.   1/9 days
	D.  1/12 days

Solution

(A+B)'s 1 day's work = 1/4 A's 1 day's work = 1/12 B's 1 day's work = (1/4 - 1/12) = 1/6. Hence, B alone can complete the work in 6 days.

20.	A and B together can do a piece of work in 30 days. A having worked for 16 days, B finishes the remaining work in 44 days. In how many days shall B finish the whole work alone?
	A.  30 days
	B.  40 days
	C.  60 days
	D.  70 days

Solution

A's 1 day's work = x B's 1 day's work = y Then, x+y = 1/30 and 16x+44y = 1. Solving these two equations, we get x=1/10 and y=1/60 Therefore B's 1 day's work= 1/60.