## Times and Work For SBI PO Set – 08

1) A contractor undertook to finish a work in 150 days and employed 75 men. After 60 days he found that he had already done 2/3 of the work . how many men can be discharged now so that the work may finish in time.

a) 60

b) 25

c) 35

d) 50

e) 45

d) 50

Explanation

M1=75, M2=75-x

D1=60,  D2=90

According to formula

= 50

2) From a group of 3 men, 4 women and 2 children, 4 people are to be chosen to form a committee. What is the probability that the committee contains 1 each of men, women and children?

a) 4/15

b) 12/ 21

c) 4/19

d) 11/31

e) None of these

b) 12/ 21

Explanation

Case 1: Prob. when 2 men, 1 woman and 1 child

Case 2: Prob. when 1 man, 2 women and 1 child

Case 3: Prob. when 1 man, 1 woman and 2 children

3) P, Q and R can complete a piece of work in 9, 18 and 27 days respectively. After 1/3 work is completed P left the work and the remaining work is completed by Q and R together. Find the days required to complete the remaining work.

a) 36/7

b) 35/6

c) 36/5

d) 32/5

e) None of these

c) 36/5

Explanation

4) 3 men and 4 women can complete a piece of work in 12 days while the same is finished by 2 men and one woman in 15 days. A boy who is 25% less efficient than that of man can complete the piece of work in how many days.

a) 400/11

b) 420/11

c) 430/11

d) 450/11

e) None of these

a) 400/11

Explanation

Solution:

5) A man and a boy received Rs 800 as wages for 5 days for the work they did together. The man’s efficiency in the work was three times that the boy. What is the daily wages of the boy ?

a)  Rs. 76

b)  RS. 56

c Rs.  44

d) Rs. 40

e) None of these

d) Rs. 40

Explanation

Man : boy

3 : 1

6) The wages of 45 women is Rs. 15525 in 48 days. If daily wages of a man are double that of a women, then the number of men required to work for 16 days to receive Rs 5750 will be?

a) 30

b) 25

c) 20

d) 35

e) 40

b) 25

Explanation

x = 50

daily wages of a man are double that of a woman.

Hence, the number of men = 25

7) Archana is thrice as good as Ragavi and together finish a piece of work in 21 days. Archana alone can finish the work in how many days?

a) 28

b) 14

c) 35

d)  42

e)  None of these

a) 28

Explanation

(Archana’s 1 day’s work) : (Rahavi’s 1 day’s work) = 3 : 1
Now,
(A rchana+ Ragav)’s 1 day’s work = 1/21
Archana’s 1 day’s work = (1/21) x 3/4 = 1/28
A alone can finish the work in 28 days.

8. If 2 men or 4 women can complete piece of work in 42 days. In how many days 4 men and 4 women complete the same piece of work?

a) 21

b) 14

c) 18

d) 20

e) None of these

b) 14

Explanation

2 men = 4 women

1 men = 2 women

4 men + 4 women=6 men

2 men complete work in 42 days

6 men can complete it in x days

x = (2 x 42)/6

6 men complete a work in 14 days

9. Radha can wash a clothes in 20 minutes, but with the help of her sister she washes the clothes in 12 minutes . In what time her sister alone can wash all the clothes

a) 30 mins

b) 25 mins

c) 20 mins

d) 15 mins

e) None of these

a) 30 mins

Explanation

60(Total work=60 parts) (LCM OF 20 AND 30)

Radha   20          3 (one min work)

Sister    30          2         “

sister alone do it in  60/2=30 min

10. Arjun and Bama can do a piece of work in 20 days ,Bama and Chitra can do a piece of work in 36 days,Arjun and Chitra can do a piece of work in 30 days. In how many days , Arjun ,Bama and Chitra can complete the whole work,working together?

a) 10

b) 13

c) 12

d) 18

e) 15

a) 10

Explanation

Total work=180 parts(LCM of 20,26,30)

Arjun and Bama   20                 9  (one day work)

Bama and Chitra  36                 5           “

Arjun and Chitra  30                 6            “

2(Arjun + Bama + Chitra)     20           “

Arjun + Bama + Chitra      10           “

whole work completed by    Arjun + Bama + Chitra=(total work)/one day work

=180/10

=18days