CAT Time & Work Questions

Time and work questions treat productivity as a rate. Workers, machines and pipes can contribute positive or negative rates, depending on whether they complete or undo the work.

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Key concepts

• Work rates and efficiency
• Combined and alternating work
• Inlets, outlets and negative rates

CAT time & work practice questions

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Common mistakes

• Adding completion times rather than rates.
• Treating workers with different efficiencies as interchangeable.

Practical solving approaches

• Choose a convenient total workload and express every contribution per unit time.
• Split changing schedules into intervals and add the work completed in each interval.

Time & Work FAQs

How do I combine two workers' times?

Convert each completion time to a rate, add the rates when they work together, then divide the total work by the combined rate.

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CAT Time & Work Questions

Time and work questions treat productivity as a rate. Workers, machines and pipes can contribute positive or negative rates, depending on whether they complete or undo the work.

10 free practice questions

Key concepts

• Work rates and efficiency
• Combined and alternating work
• Inlets, outlets and negative rates

CAT time & work practice questions

Question 1Type in the answerMEDIUM

Question 1

Type in your answer in the input box provided below the question.

Answer the questions independently of each other.

A can finish a work in 20 days and B can finish it in 30 days. If both A and B are working on a project which pays them a total amount of 500 Rs. for their work, then how much money A will get?

Your answer

Check answerView solution

Question 2Type in the answerEASY

Question 2

Type in your answer in the input box provided below the question.

Answer the questions independently of each other.

Pipe A empties a tank in 104 minutes and pipe B empties the tank in 80 minutes. By what percentage is the efficiency of pipe B more than that of pipe A.

Your answer

Check answerView solution

Question 3Multiple choiceMEDIUM

Question 3

Select the correct alternative from the given choices.

Answer the questions independently of each other.

Ten cows can graze in a field for 15 days and twenty cows can graze in the same field for 6 days. For how many days can thirty cows graze in the same field?

Choose an answer

A.3 daysB.3.67 daysC.3.75 daysD.Cannot be determined

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Question 4Multiple choiceMEDIUM

Question 4

Select the correct alternative from the given choices.

Answer the questions independently of each other.

Two persons A and B could finish a work in x days. Initially, B worked for y days and was later joined by A. The remaining work was completed by them in z days. In how many days could each of them finish the work?

Choose an answer

A.

B.

C.

D.

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Question 5Multiple choiceHARD

Question 5

Select the correct alternative from the given choices.

Answer the questions independently of each other.

Three pipes P, Q and R, when functioning alone, can fill a pool in 4, 8 and 12 hours respectively, while another pipe S, functioning alone, can empty the completely filled pool in 10 hours. Which of the following arrangements will fill the pool in the least possible time?

Choose an answer

A.Q alone is opened.B.P and S are opened together.C.P, Q and S are opened together.D.Q, R and S are opened together.

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Question 6Type in the answerMEDIUM

Question 6

Enter your response (as an integer) using the virtual keyboard in the box provided.

Three flexible pipes that can serve as inlet as well as outlet pipes have been attached to a tank. The rates of filling
or emptying the tank by these three pipes are in the ratio 1 : 2 : 4. The largest pipe can alone fill the empty tank in
7 hours. Initially the tank is full and the three pipes were used as outlet pipes for ‘M’ hours. After the tank is
emptied, later the smallest pipe alone filled the entire tank in 28 hours. Find the value of ‘M’.

Your answer

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Question 7Multiple choiceMEDIUM

Question 7

Select the correct alternative from the given choices

There are four machines that make gears for a factory. The fastest machine can make one gear in two hours. The
slowest machine makes one gear in 3 hours. Which of the following cannot be the value of the average time taken (in hours)
by the four machines to make a gear?

Choose an answer

A.2.2B.2.3C.2.6D.2.68

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Question 8Type in the answerMEDIUM

Question 8

Enter your response (as an integer) using the virtual keyboard in the box provided.

A group of 10 workers can plough a field in 20 days. This group starts the work and after every 2 days, 2 additional
workers join the group. The efficiency of each worker is the same. On which day workers finish ploughing the
field?

Your answer

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Question 9Multiple choiceMEDIUM

Question 9

After how much me from the start is the vessel empty for the first time?

An empty vessel is connected with 3 pipes A, B, and C. Pipe A and Pipe B can fill the empty vessel in 4 and 2 minutes respectively
while the pipe C can empty the completely filled vessel in 1 minute. Pipe A is opened first and pipe B is opened after 1 minute and
the outlet pipe C is opened after 1 more minute.

Choose an answer

A.2 minutesB.3 minutesC.6 minutesD.The vessel can never be empty

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Question 10Multiple choiceMEDIUM

Question 10

Select the correct alternative from the given choices

In a shoe manufacturing factory, 18 men manufacture 20 shoes in 10 days working for 7.5 hours a day. How long will it take for 36
men to manufacture 40 shoes working 6 hours a day? It is also known that 4 men in the former case do as much work as 6 men in the
former.

Choose an answer

A.20/3 daysB.25/3 daysC.35/3 daysD.Cannot be determined

Check answerView solution

Common mistakes

• Adding completion times rather than rates.
• Treating workers with different efficiencies as interchangeable.

Practical solving approaches

• Choose a convenient total workload and express every contribution per unit time.
• Split changing schedules into intervals and add the work completed in each interval.

Time & Work FAQs

How do I combine two workers' times?

Convert each completion time to a rate, add the rates when they work together, then divide the total work by the combined rate.

More Arithmetic practice

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