TIME & WORK SET 5

Q.1 A certain no. of men complete a work in 60 days. If there were 8 men more work could be finished in 10 days less. How many men were originally there ?
A) 40
B) 41
C) 42
D) 43
Ans. A
Shortcut:
No. of more men * (60-10) / 10
8*50/10=40

Q.2 A can do work in 7 days. If A does twice as much work as B in a given time, find how long A & B would take to do the work ?
A) 4 2/4 days
B) 5 2/3 days
C) 4 2/3 days
D) 5 2/4 days
Ans. C
Shortcut:
A+B=xy/x+y
i.e. 7*14/14+7
= 4 2/3 days

Q.3 10 men can finish a work in 10 days where it takes 12 women to finish it in 10 days. If 15 men & 6 women undertake to complete the work how many days will they take to complete it ?
A) 5 days
B) 6 days
C) 7 days
D) 8 days
Ans. A
15 men=10*10/15
=20/3 days
6 women=12*10/6
=20 days
15men+6women=20/3 * 20 / 20/3+20 (we have used this formula: x*y/x+y)
20*20/80
=5 days

Q.4 A,B & C can finish a work in 10,12 & 15 days. If B stops after 2 days how long would it take to A & C to finish the remaining work ?
A) ½ work
B) 1/3 work
C) ¼ work
D) 1/5 work
Ans. A
Shortcut:
2 (1/10 + 1/15 + 1/12)
Or 2*1/4
=1/2 work

Q.5 A is twice as good as workman as B. Together they finish in 14 days. In how many days can it be done by each separately ?
A) 21 days
B) 22 days
C) 23 days
D) 24 days
Ans. A
Shortcut:
(Twice + one) = Thrice in 14 days
i.e. 14 * 3 = 42 days
or twice person = 42 / 2 = 21 days