Time and Work - General Questions (4)

25.

If 6 men and 8 boys can do a piece of work in 10 days while 26 men and 48 boys can do the same in 2 days, the time taken by 15 men and 20 boys in doing the same type of work will be:

A.	4 days
B.	5 days
C.	6 days
D.	7 days

Answer: Option A

Explanation:

Let 1 man's 1 day's work = x and 1 boy's 1 day's work = y.

Then, 6x + 8y =	1	and 26x + 48y =	1	.
	10		2

Solving these two equations, we get : x =	1	and y =	1	.
	100		200

(15 men + 20 boy)'s 1 day's work =		15	+	20		=	1	.
		100		200			4

15 men and 20 boys can do the work in 4 days.

26.

A alone can do a piece of work in 6 days and B alone in 8 days. A and B undertook to do it for Rs. 3200. With the help of C, they completed the work in 3 days. How much is to be paid to C?

A.	Rs. 375
B.	Rs. 400
C.	Rs. 600
D.	Rs. 800

Answer: Option B

Explanation:

C's 1 day's work =	1	-		1	+	1		=	1	-	7	=	1	.
	3			6		8			3		24		24

A's wages : B's wages : C's wages =	1	:	1	:	1	= 4 : 3 : 1.
	6		8		24

C's share (for 3 days) = Rs.		3 x	1	x 3200		= Rs. 400.
			24

27.

A is thrice as good as workman as B and therefore is able to finish a job in 60 days less than B. Working together, they can do it in:

A.	20 days
B.	22 1/2 days
C.	25 days
D.	30 days

Answer: Option B

Explanation:

Ratio of times taken by A and B = 1 : 3.

The time difference is (3 - 1) 2 days while B take 3 days and A takes 1 day.

If difference of time is 2 days, B takes 3 days.

If difference of time is 60 days, B takes		3	x 60		= 90 days.
		2

So, A takes 30 days to do the work.

A's 1 day's work =	1
	30

B's 1 day's work =	1
	90

(A + B)'s 1 day's work =		1	+	1		=	4	=	2
		30		90			90		45

A and B together can do the work in	45	= 22	1	days.
	2		2

28.

A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if he is assisted by B and C on every third day?

A.	12 days
B.	15 days
C.	16 days
D.	18 days

Answer: Option B

Explanation:

A's 2 day's work =		1	x 2		=	1	.
		20				10

(A + B + C)'s 1 day's work =		1	+	1	+	1		=	6	=	1	.
		20		30		60			60		10

Work done in 3 days =		1	+	1		=	1	.
		10		10			5

Now,	1	work is done in 3 days.
	5

Whole work will be done in (3 x 5) = 15 days.

29.

A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. Then, C alone can do the job in:

A.	9 1/5 days
B.	9 2/5 days
C.	9 3/5 days
D.	10

Answer: Option C

Explanation:

(A + B + C)'s 1 day's work =	1	,
	4

A's 1 day's work =	1	,
	16

B's 1 day's work =	1	.
	12

C's 1 day's work =	1	-		1	+	1		=		1	-	7		=	5	.
	4			16		12				4		48			48

So, C alone can do the work in	48	= 9	3	days.
	5		5

30.

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

Answer: Option D

Explanation:

A's 1 day's work =	1	;
	15

B's 1 day's work =	1	;
	20

(A + B)'s 1 day's work =		1	+	1		=	7	.
		15		20			60

(A + B)'s 4 day's work =		7	x 4		=	7	.
		60				15

Therefore, Remaining work =		1 -	7		=	8	.
			15			15

Time and Work - General Questions (4)

Questions & Answers

Interviews

Jobs

Results

Admission

Admit Card

Answer Key