1.A is thrice efficient as B and C is twice as efficient as
B. What is the ratio of number of days taken by A, B and C, when they work
individually?
(a) 2 : 6 : 3
(b) 2 : 3 : 6
(c) 1 : 2 : 3
(d) 3 : 1 : 2
2.A and B can complete a task in 30 days when working together
after A and B have been working together for 11 days. B is called away and A,
all by himself completes the task in the next 28 days. Had A been working
alone, the number of days taken by him to complete the task would have
been:
(a) 33 3/19
(b) 19 6/25
(c) 44 4/19
(d) none of these
3.Sonu can do a piece of work in 20 days. He started the work and
left after some days, when 25% work was done. After it Abhijeet joined
and completed it working for 10 days. In how many days Sonu and Abhijeet can do
the complete work, working together?
(a) 6
(b) 8
(c) 10
(d) 12
4.Chandni and Divakar can do a piece of work in 9 days and 12 days
respectively. If they work for a day alternatively, Chandni beginning, in how
many days, the work will be completed?
(a) 10 ¼
(b) 9 1/5
(c) 11 : 11
(d) 10
5.Fatima and Zahira can do a piece of work in 12 days and 15 days
respectively. If they work for alternate day and Fatima starts the work first,
then in how many days the work will be completed?
(a) 12 1/5
(b) 13 1/4
(c) 13 1/5
(d) 15
6.A takes 6 days less than B to do a certain job and 2 days more
than C. A and B together can do the work in the same time as C. In how many
days B alone can do the complete work?
(a) 10
(b) 14
(c) 12
(d) 16
7.When A, B and C are deployed for a task, A and B together
do 70% of the work and B and C together do 50% of the work who is most
efficient?
(a) A
(b) B
(c) C
(d) can’t be determined
8.A piece of work can be completed by 10 men and 6 women in 18
days. Men works 9 hours per day while women works 7. 5 hours per day. Per hour
efficiency of a woman is 2/3rd of a man’s efficiency. In how many days 10 men
and 9 women complete the work?
(a) 16 days
(b) 20 days
(c) 30 days
(d) 2 days
9.A can do a piece of work in 2 hours, B can do thrice the work in
8 hours and ‘C’ can do the same work as A in 8 hours . If all of them work
together, how long it would take them to complete the work:
(a) 1 hour
(b) 2 hours
(c) 3 hours
(d) 4 hours
10.4 men and 2 boys can finish a piece of work in 5 days. 3
women and 4 boys can finish the same work in 5 days. Also 2 men and 3
women can finish the same work in 5 days. In how many days 1 man, 1 woman and
one boy can finish the work, at their double efficiency?
(a) 4 8/13
(b) 4 7/13
(c) 3 7/13
(d) none of these
ANSWERS AND SOLUTION :
1.(a)
2.(c)
Work done in 11 days = 11/30
Rest work = 19/30
1 day’s work of A = (19/30)/28 = 19/(30*28) = 19/840
Total number of days required to complete the whole work alone
= 1/(19/840) = 840/19 = 44 4/19days
3.(b)
Efficiency of Sonu = 5% = (100/20)
Rest work = 75%
so Efficiency of Abhijeet = 75/10 = 7.5%
so Combined efficiency of Sonu and Abhijeet
= 12. 5% = (7.5 + 5)
so Number of days required by Sonu and Abhijeet, to work together
= 100/12.5 = 8 days
4.(a)
5.(b)
6.(c)
Let B takes x days to complete the work individually,
Then, the B’s 1 day’s work = 1/x
A’s 1 day’s work = 1/(x -6)
C’s 1 day’s work = 1/(x – 8)
so 1/(x-6) + 1/x + 1/(x – 8)
Now either solve the equation or satisfy the equation from the choices given in the question.
Thus option (c) in correct.
7.(a)
8.(a)
Work of a man for 1 hour = 3/2 women’s work for 1 hour
again, work of a man for 1 day
= (3/2 ×9/7.5) women’s work for 1 hour
=>Work of a man for 1 day = 9/5 women’s work for 1 day
=>1 man = 9/5 women
so 10 men + 6 women = 10 * 9/5 + 6 = 24 women
so 10 men + 9 women = 10 * 9/5 + 9 = 27 women
Now,
D1 * W1 = D2 * W2
18 * 24 = D2 * 27
D2 = 16 days
9.(a)
10.(b)
Efficiency of 4 men and 2 boys = 20%
Efficiency of 3 women and 4 boys = 20%
Efficiency of 2 men and 3 women = 20%
so Efficiency of 6 men, 6 women and 6 boys = 60%
so Efficiency of 1 man, 1 women and 1 boy = 10%
Now, since they will work at double their efficiency
so Efficiency of1 man, 1 woman and 1 boy = 20%
so Required number of days = 5
1.(a)
2.(c)
Work done in 11 days = 11/30
Rest work = 19/30
1 day’s work of A = (19/30)/28 = 19/(30*28) = 19/840
Total number of days required to complete the whole work alone
= 1/(19/840) = 840/19 = 44 4/19days
3.(b)
Efficiency of Sonu = 5% = (100/20)
Rest work = 75%
so Efficiency of Abhijeet = 75/10 = 7.5%
so Combined efficiency of Sonu and Abhijeet
= 12. 5% = (7.5 + 5)
so Number of days required by Sonu and Abhijeet, to work together
= 100/12.5 = 8 days
4.(a)
5.(b)
6.(c)
Let B takes x days to complete the work individually,
Then, the B’s 1 day’s work = 1/x
A’s 1 day’s work = 1/(x -6)
C’s 1 day’s work = 1/(x – 8)
so 1/(x-6) + 1/x + 1/(x – 8)
Now either solve the equation or satisfy the equation from the choices given in the question.
Thus option (c) in correct.
7.(a)
8.(a)
Work of a man for 1 hour = 3/2 women’s work for 1 hour
again, work of a man for 1 day
= (3/2 ×9/7.5) women’s work for 1 hour
=>Work of a man for 1 day = 9/5 women’s work for 1 day
=>1 man = 9/5 women
so 10 men + 6 women = 10 * 9/5 + 6 = 24 women
so 10 men + 9 women = 10 * 9/5 + 9 = 27 women
Now,
D1 * W1 = D2 * W2
18 * 24 = D2 * 27
D2 = 16 days
9.(a)
10.(b)
Efficiency of 4 men and 2 boys = 20%
Efficiency of 3 women and 4 boys = 20%
Efficiency of 2 men and 3 women = 20%
so Efficiency of 6 men, 6 women and 6 boys = 60%
so Efficiency of 1 man, 1 women and 1 boy = 10%
Now, since they will work at double their efficiency
so Efficiency of1 man, 1 woman and 1 boy = 20%
so Required number of days = 5
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