Learn and practice the chapter "Time and Work" with these solved Aptitude Questions and Answers. Each question in the topic is accompanied by a clear and easy explanation, diagrams, formulae, shortcuts and tricks that help in understanding the concept.
Use of Time and Work Questions
The questions and examples given in this section will be useful to all the freshers, college students and engineering students preparing for placement tests or any competitive exam like MBA, CAT, MAT, SNAP, MHCET, XAT, NMAT, GATE, Bank exams - IBPS, SBI, RBI, RRB, SSB, SSC, UPSC etc.
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1. Amish is 5 times as efficient as Brijesh. Amish can finish the work 60 days earlier than Brijesh. If they work individually, how many days would they take to finish the work?
a. Amish = 10 days; Brijesh = 50 days
b. Amish = 15 days; Brijesh = 75 days
c. Amish = 20 days; Brijesh = 80 days
d. Amish = 20 days; Brijesh = 100 days
Answer: b. Amish = 15 days; Brijesh = 75 days
Explanation:
Speed of Work / Efficiency ∝
1
Time needed
So more the efficiency, less time is needed to do the task.
Let us denote Amish by 'A' and Brijesh by 'B'
Hence, if A is 5 times faster than B, then B needs 5 times more time than A.
Let A need 'n' days to complete the work.
So B will need 5n days.
Also, 5n – n = 60 ------------------- Given
∴ n = 15 days = Days needed by A to complete work individually Days needed by B to complete work individually = 5n = 5 x 15 = 75 days
Video : Time and Work in Hindi - Simple Aptitude tricks for freshers
2. Recollecting the progress of an assignment, a group of 24 men said that they finished a project together in 10 days. Find the number of days required to complete the same work if 30 men had worked on the same project.
a. 3 days
b. 6 days
c. 7.5 days
d. 8 days
Answer: d. 8 days
Explanation:
24 men complete work in 10 days.
∴ In 1 day work done by 24 men =
1
10
In 1 day work done by 30 men = ?
∴ ? x 24 =
1
x 30
10
∴ ? =
1
= Amount of work done by 30 men in one day
8
Tip:
If A completes work in 'n' days, in 1 day he completes
1
amount of work.
n
Conversely, if A completes
1
amount of work in 1 day, he completes entire work in 'n' days.
n
Thus in this case, 30 men complete entire work in 8 days.
3. Working individually, A would finish a project in 3 days. B takes double the time as taken by A, C takes one more day in addition to the time taken by B. If all three of them decide to work together on the project, how much time would they take to finish it?
a.
15
Days
16
b.
11
Days
10
c.
14
Days
9
d.
16
Days
7
Answer: c.
14
Days
9
Explanation:
A can do the work in 3 days. So in 1 day A does
1
amount of work
3
B takes double the time as A. So, B can do the work in 6 days. So, in 1 day B does
1
amount of work
6
C takes one more day in addition to the time taken by B. So, C can do the work in 7 days.
So, in 1 day C does
1
amount of work
7
When they work together, in 1 day they complete how much work?
In one day - A, B and C together complete =
1
+
1
+
1
=
9
amount of work
3
6
7
14
Tip:
If A completes
1
amount of work in 1 day, he completes entire work in 'n' days.
n
A, B and C together complete the entire work in
14
days.
9
4. Working on an assignment together, Pam and Ken can finish it in12 days. Ken and Ron need 4 days more than Pam and Ken to finish the assignment while Ron and Pam together would take 3 weeks and 3 days to finish the same assignment. If all of them are allowed to work together on the assignment, how much time would they take to finish the assignment?
a. 9
3
days
4
b. 10 days
c. 10
2
days
3
d. 11
1
days
4
Answer: c. 10
2
days
3
Explanation:
Let us denote Pam by 'P', Ken by 'K' and Ron by 'R'
P + K can do the work in 12 days. So, in 1 day they do
1
amount of work
12
K + R take four days more than P + K. So, they do the work in 16 days. So, in 1 day they do
1
amount of work
16
R + P can do the work in 3 week and 3 days, which is 24 days. So, in 1 day they do
1
amount of work
24
Adding these, (P+K)+(K+R)+(R+P) =
1
+
1
+
1
=
3
12
16
24
16
∴ 2(P+K+R) =
3
16
P+K+R =
3/16
=
3
= Work done in 1 day by P, K and R together
2
32
Tip:
If A completes
1
amount of work in 1 day, he completes entire work in 'n' days.
n
P, K and R together complete the entire work in
32
days. = 10
2
days
3
3
5. Working alone Pramod takes complete April to build a pavement. His friend Kishan is 25% faster than him at the same work. Working alone, how many days will Kishan take to build the same pavement?
a. 20 days
b. 24 days
c. 22.5 days
d. 37.5 days
Answer: b. 24 days
Explanation:
April has 30 days. So Pramod takes 30 days to build the pavement.
Kishan is 25% faster than Pramod
25% =
25
= 0.25
100
This means, if Pramod is 1, then Kishan is (1+0.25) = 1.25
Pramod takes 30 days to do the work.
