Time and Work Quiz Set 015


Your Score
Correct Answers:
Wrong Answers:
Unattempted:

Question 1

A and B can together complete a job in 10 days. A can alone complete it in 15 days. How long would B alone take to finish the job?

 A

30 days.

 B

31 days.

 C

29 days.

 D

33 days.

Soln.
Ans: a

One day work of A + B is $1/10$. One day work of A is $1/15$. So one day work of B, say, $1/y$ = $1/10$ - $1/15$. Solving, we get y = 30 days.


Question 2

If 45 men can do a task in 5 days, how many men are required to complete the task in 9 days?

 A

25.

 B

10.

 C

8.

 D

12.

Soln.
Ans: a

If m1 men can do a task in d1 days, and m2 in d2, then we must have m1 × d1 = m2 × d2. Putting m1 = 45, d1 = 5 and d2 = 9, we get m2 = 25.


Question 3

A and B can together complete a job in 16 days. A can alone complete it in 24 days. How long would B alone take to finish the job?

 A

48 days.

 B

49 days.

 C

47 days.

 D

51 days.

Soln.
Ans: a

One day work of A + B is $1/16$. One day work of A is $1/24$. So one day work of B, say, $1/y$ = $1/16$ - $1/24$. Solving, we get y = 48 days.


Question 4

A, B and C complete a work in 9, 3 and 19 days respectively. All three of them start the work together, but A leaves the work after 1 days. In how many days will the work be completed?

 A

$2{10/33}$ days.

 B

$3{10/33}$ days.

 C

$4{10/33}$ days.

 D

$5{10/33}$ days.

Soln.
Ans: a

Use the shortcut formula. If A, B, C can independently complete the job in x, y and z days, and A leaves after n days, the work is completed in ${yz}/{y + z}$ × $(1 - n/x)$ days. Putting the various values x = 9, y = 3, z = 19, n = 1, and simplifying, we get ${76/33}$, which is same as: $2{10/33}$.


Question 5

A, B and C can independently complete a work in 16, 3 and 13 days respectively. First C starts the work, then A joined after 1 days, and B after 2 days. In how many days was the work completed?

 A

$3{194/295}$ days.

 B

$4{194/295}$ days.

 C

$5{194/295}$ days.

 D

$6{194/295}$ days.

Soln.
Ans: a

Use the shortcut formula. If A, B, C can independently complete the job in x, y and z days, and A joins after n days, and B joins after m days, the work is completed in ${xyz}/{xy + yz + zx}$ × $(1 + n/x + m/y)$ days. Putting the various values x = 16, y = 3, z = 13, n = 1, m = 2, and simplifying, we get ${1079/295}$, which is same as: $3{194/295}$.


buy aptitude video tutorials


Creative Commons License
This Blog Post/Article "Time and Work Quiz Set 015" by Parveen (Hoven) is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Updated on 2020-02-07. Published on: 2016-05-03

Posted by Parveen(Hoven),
Aptitude Trainer


Comments and Discussion