Time and work questions

Aptitude Updated 11 Oct 2026

These time and work questions cover the problems asked in SSC, bank, railway and placement aptitude tests: working together, one person leaving, alternate days, efficiency, man-days and sharing wages. Each question has four options, the answer and the full working.

Start with the basic set, move on to the questions where a worker joins or leaves, and finish with efficiency and wages. Solve each one on paper first, then compare your steps with the explanation.

Answered 0 / 30Right 0Wrong 0

Basic time and work questions

Q1. A can finish a piece of work in 12 days and B can finish it in 24 days. In how many days can they finish it working together?
Show answer
Answer: D. 8 days
One day's work = 1/12 + 1/24 = 3/24 = 1/8. So together they take 8 days.
Q2. Ravi can do a job in 10 days and Sohan can do it in 15 days. How long will they take to do it together?
Show answer
Answer: B. 6 days
Together per day: 1/10 + 1/15 = 5/30 = 1/6. So they need 6 days.
Q3. A and B together finish a work in 20 days. A alone can finish it in 30 days. In how many days can B alone finish it?
Show answer
Answer: B. 60 days
B's one day work = 1/20 - 1/30 = 1/60. So B alone takes 60 days.
Q4. A, B and C can do a work in 6, 8 and 12 days respectively. In how many days will all three together finish it?
Show answer
Answer: A. 2 2/3 days
Together per day: 1/6 + 1/8 + 1/12 = (4 + 3 + 2)/24 = 9/24 = 3/8. Time = 8/3 = 2 2/3 days.
Q5. 15 workers can build a wall in 12 days. How many days will 10 workers take to build the same wall?
Show answer
Answer: C. 18 days
Total work = 15 x 12 = 180 worker-days. Time for 10 workers = 180 / 10 = 18 days.
Q6. 8 men can finish a job in 20 days. How many men are needed to finish it in 10 days?
Show answer
Answer: D. 16 men
Total work = 8 x 20 = 160 man-days. Men needed = 160 / 10 = 16.
Q7. A can complete a work in 9 days. What fraction of the work will A complete in 3 days?
Show answer
Answer: A. 1/3
One day's work = 1/9, so 3 days' work = 3 x 1/9 = 1/3.
Q8. Three equally skilled workers can each finish a task alone in 18 days. How long will the three take if they work together?
Show answer
Answer: D. 6 days
Each does 1/18 per day, so together 3/18 = 1/6 per day. They need 6 days.
Q9. A tap-repair job takes a plumber 4 hours alone and his helper 12 hours alone. How long will they take working together?
Show answer
Answer: B. 3 hours
Per hour together: 1/4 + 1/12 = 4/12 = 1/3. So they need 3 hours.
Q10. A and B together can do a work in 9 days, and B alone can do it in 12 days. In how many days can A alone do it?
Show answer
Answer: A. 36 days
A's work per day = 1/9 - 1/12 = (4 - 3)/36 = 1/36. So A alone needs 36 days.

Working together, leaving and alternate days

Q11. A can do a work in 20 days and B in 30 days. They work together for 6 days, and then A leaves. In how many more days will B finish the remaining work?
Show answer
Answer: C. 15 days
In 6 days they do 6 x (1/20 + 1/30) = 6 x 1/12 = 1/2. B finishes the other 1/2 in (1/2) x 30 = 15 days.
Q12. A can do a work in 10 days. A works on it for 4 days, and B finishes the rest in 9 days. In how many days can B alone do the whole work?
Show answer
Answer: A. 15 days
A does 4/10 = 2/5 of the work. B does the remaining 3/5 in 9 days, so B alone needs 9 x 5/3 = 15 days.
Q13. A can do a work in 12 days and B in 16 days. They start together, but A leaves 3 days before the work is finished. In how many days is the work finished in all?
Show answer
Answer: B. 8 4/7 days
Let the total be T days. B works T days, A works T - 3 days: T/16 + (T - 3)/12 = 1, so 3T + 4T - 12 = 48 and T = 60/7 = 8 4/7 days.
Q14. A can finish a work in 10 days and B in 15 days. They work on alternate days, with A starting on the first day. In how many days will the work be finished?
Show answer
Answer: C. 12 days
Every 2 days they do 1/10 + 1/15 = 1/6 of the work. So 6 such pairs finish it: 6 x 2 = 12 days.
Q15. A and B can do a work in 15 days, B and C in 20 days, and C and A in 30 days. In how many days can A, B and C together do it?
Show answer
Answer: A. 13 1/3 days
2(A + B + C) = 1/15 + 1/20 + 1/30 = 9/60 = 3/20, so A + B + C = 3/40 per day. Time = 40/3 = 13 1/3 days.
Q16. A and B can finish a work in 15 days, B and C in 20 days, and C and A in 30 days. How long will A alone take?
Show answer
Answer: C. 40 days
A + B + C = 3/40 per day and B + C = 1/20 = 2/40. So A = 1/40 per day, and A alone takes 40 days.
Q17. A can finish a work in 18 days. After A has worked alone for 6 days, B joins him and the two finish the work in 4 more days. How long would B alone take?
Show answer
Answer: D. 9 days
A works 10 days in all and does 10/18 = 5/9. B does 4/9 in 4 days, so B alone needs 9 days.
Q18. 12 men start a work that they can finish in 18 days. After 6 days, 4 men leave. In how many more days will the remaining men finish the work?
Show answer
Answer: A. 18 days
Total work = 12 x 18 = 216 man-days. Done in 6 days = 72, left = 144. 8 men need 144 / 8 = 18 days.
Q19. A works twice as fast as B. Together they finish a work in 12 days. In how many days can A alone finish it?
Show answer
Answer: D. 18 days
If B does b per day, A does 2b, so 3b = 1/12 and b = 1/36. A does 1/18 per day, so A alone takes 18 days.
Q20. A can do a work in 15 days and B in 20 days. If they work together for 4 days, what fraction of the work is left?
Show answer
Answer: D. 8/15
Together per day: 1/15 + 1/20 = 7/60. In 4 days they do 28/60 = 7/15, so 1 - 7/15 = 8/15 is left.

Efficiency, men-days and wages

Q21. A is 30% more efficient than B. If B can finish a work in 26 days, how long will A take?
Show answer
Answer: B. 20 days
Time is inversely proportional to efficiency. A's time = 26 / 1.3 = 20 days.
Q22. A can finish a work in 20 days and B in 26 days. How long will they take working together?
Show answer
Answer: C. 11 7/23 days
Together per day: 1/20 + 1/26 = (13 + 10)/260 = 23/260. Time = 260/23 = 11 7/23 days.
Q23. A can do a work in 10 days and B in 15 days. They do it together and get Rs 1,500. What is A's share?
Show answer
Answer: C. Rs 900
Shares follow the work done per day, 1/10 : 1/15 = 3 : 2. A gets (3/5) x 1500 = Rs 900.
Q24. A alone can do a work in 6 days and B alone in 8 days. With the help of C, they finish it in 3 days and are paid Rs 3,200. How much should C get?
Show answer
Answer: A. Rs 400
In 3 days A does 3/6 = 1/2 and B does 3/8, so C does 1 - 1/2 - 3/8 = 1/8. C's share = 3200 x 1/8 = Rs 400.
Q25. 2 men or 3 women can finish a work in 18 days. In how many days will 4 men and 6 women finish it together?
Show answer
Answer: B. 4 1/2 days
2 men = 3 women, so 4 men = 6 women and the group equals 12 women. Work = 3 x 18 = 54 woman-days, so time = 54 / 12 = 4 1/2 days.
Q26. 10 men working 8 hours a day finish a work in 12 days. How many days will 6 men take if they also work 8 hours a day?
Show answer
Answer: B. 20 days
Using M1 x D1 x H1 = M2 x D2 x H2: 10 x 12 x 8 = 6 x D x 8, so D = 120 / 6 = 20 days.
Q27. 16 workers working 9 hours a day can do a job in 10 days. In how many days can 12 workers do it working 8 hours a day?
Show answer
Answer: A. 15 days
16 x 9 x 10 = 1440 worker-hours. 12 workers x 8 hours = 96 worker-hours per day, so 1440 / 96 = 15 days.
Q28. A is three times as efficient as B, so A takes 40 days less than B to finish a work. How long will they take working together?
Show answer
Answer: B. 15 days
If A takes x days, B takes 3x days, so 3x - x = 40 and x = 20. Together: 1/20 + 1/60 = 4/60 = 1/15, so 15 days.
Q29. A completes 3/4 of a work in 15 days. How many days will A need to complete the whole work?
Show answer
Answer: D. 20 days
Whole work time = 15 / (3/4) = 15 x 4/3 = 20 days.
Q30. 4 women or 6 children can finish a work in 12 days. In how many days will 3 women and 3 children finish it?
Show answer
Answer: C. 9 3/5 days
6 children = 4 women, so 3 children = 2 women and the group equals 5 women. Work = 4 x 12 = 48 woman-days, so time = 48/5 = 9 3/5 days.

How to prepare

The key idea is one day's work. If a person finishes a job in n days, he does 1/n of it each day. Add the daily rates of people working together, subtract a known rate to find an unknown one, and take the reciprocal to get the time. When a worker joins or leaves, find the work done in each stage and add the stages to make 1.

For groups of workers use the chain rule M1 x D1 x H1 = M2 x D2 x H2. For efficiency, time is inversely proportional to efficiency, so a worker 25% more efficient takes 4/5 of the time. Wages are always shared in the ratio of the work done, not the days worked. A quick shortcut is to take the LCM of the days as total work units.

Study tips

Take the LCM of the given days as the total work so that every daily rate becomes a whole number.
Write the work done in each stage separately when someone joins or leaves, then make the total equal 1.
For wage questions, divide the money in the ratio of work done by each person.

Questions people ask

How do I solve time and work questions quickly?

Use the LCM method: take the LCM of all the given days as the total work, find each person's units per day, and divide. This avoids fractions and saves time in exams.

What is the formula for time and work?

Work = rate x time. If A takes a days and B takes b days, together they take ab/(a + b) days. For groups, M1 x D1 x H1 = M2 x D2 x H2.

Are time and work aptitude questions asked in placement tests?

Yes. Time and work, along with pipes and cisterns, is a regular topic in campus placement and company aptitude tests as well as in SSC and bank exams.

How are wages divided in time and work questions?

Wages are divided in the ratio of the work each person does. If two people work for the same number of days, the ratio is the same as their efficiencies.

Every question on this page is written and fact-checked by the GK Quizzes team. Spotted a mistake? Tell us and we will fix it. How we make our questions.