Time and Work is one of the most common and important topics in the Quantitative Aptitude section of exams like SSC, Banking, and Railways. Questions from this topic often test your ability to calculate how quickly a task can be completed by one or more people, and how efficiently they can work together. In this blog, we will give you 20 previous year solved questions to help you score better in your exams on Time and Work including basic concepts, important formulas, short tricks, and previous year solved questions to help you score better in your exams.
Solved Time and Work Questions from Previous Year Exams
Here are some Time and Work questions that have been asked in previous year exams such as SSC CGL, SSC CHSL, SSC MTS, SSC GD Constable, Railway RRB NTPC, IBPS Clerk, IBPS PO, and SBI Clerk and SBI PO exams. Solving these questions will help you understand the exam pattern, the level of difficulty, and the types of problems commonly asked in competitive exams.
Q1. A can do a piece of work in 10 days, B in 15 days. They work together for 3 days. How much work is left?
Ans: 710\frac{7}{10}107 work left
Explanation:
A’s 1-day work = 1/10, B’s = 1/15
Together = 1/6
Work done in 3 days = 3 × 1/6 = 1/2
Remaining = 1 – 1/2 = 1/2
Q2. A and B together can do a work in 12 days. A alone can do it in 20 days. In how many days can B alone do it?
Ans: 30 days
Explanation:
A + B = 1/12
A = 1/20
B = 1/12 – 1/20 = 1/30
Q3. A does 60% of work in 12 days. How many more days to complete full work?
Ans: 8 days
Explanation:
60% = 12 days ⇒ 100% = (12/60) × 100 = 20 days
Remaining = 20 – 12 = 8 days
Q4. A can do a piece of work in 8 days, B can do the same in 12 days. They work together for 4 days. What fraction of work is left?
Ans: 13\frac{1}{3}31 work left
Explanation:
A’s 1-day work = 1/8, B’s = 1/12
Together = (3 + 2)/24 = 5/24
Work in 4 days = 4 × 5/24 = 5/6
Remaining = 1 – 5/6 = 1/6
Q5. A can do a work in 15 days and B can do it in 20 days. With help of C, they finish it in 5 days. How long will C alone take?
Ans: 60 days
Explanation:
A + B + C = 1/5
A = 1/15, B = 1/20
C = 1/5 – (1/15 + 1/20) = 1/60
Q6. A can do a job in 6 days. B is 50% more efficient than A. How many days will B take?
Ans: 4 days
Explanation:
If A takes 6 days, B’s efficiency = 150% of A
Hence, B will take = 6 × (100/150) = 4 days
Q7. A and B can do a piece of work in 10 days, B and C in 12 days, and A and C in 15 days. How long will A, B, and C together take?
Ans: 8 days
Explanation:
(A + B) = 1/10, (B + C) = 1/12, (A + C) = 1/15
Adding all: 2(A + B + C) = 1/10 + 1/12 + 1/15 = (6 + 5 + 4)/60 = 15/60
A + B + C = 15/120 = 1/8
Q8. A can do a piece of work in 5 days, B in 10 days. They start together, but B leaves after 2 days. How long will A take to finish the remaining work?
Ans: 2 more days
Explanation:
A + B in 1 day = 1/5 + 1/10 = 3/10
Work in 2 days = 6/10 = 3/5
Remaining = 2/5
A alone = (2/5) ÷ (1/5) = 2 days
Q9. A and B can do a work in 18 days and 24 days respectively. They start together, but A leaves after 6 days. How long will B take to finish the rest?
Ans: 10 days
Explanation:
A’s 1-day work = 1/18, B’s = 1/24
In 6 days, done = 6 × (1/18 + 1/24) = 6 × (7/72) = 7/12
Remaining = 5/12
B alone = (5/12) ÷ (1/24) = 10 days
Q10. A is twice as efficient as B. Together they finish a task in 12 days. How long will B take alone?
Ans: 36 days
Explanation:
Let B = 1x, A = 2x ⇒ total = 3x
3x × 12 = 1 ⇒ x = 1/36
So, B alone = 36 days
Q11. A can complete a task in 9 days and B in 18 days. They work alternately starting with A. How many days to finish the work?
Ans: 12 days
Explanation:
A’s 1-day work = 1/9, B’s = 1/18
In 2 days = 1/9 + 1/18 = 1/6
After 10 days = 5 × 1/6 = 5/6
Remaining = 1/6 (done by A on day 11)
Total = 11 days
Q12. 10 men can complete a work in 15 days. How many men are needed to finish it in 5 days?
Ans: 30 men
Explanation:
Men × Days = constant
10 × 15 = M × 5 ⇒ M = 30
Q13. A can do a work in 10 days. He works alone for 4 days, then B joins and together they finish in 2 more days. How long would B alone take?
Ans: 5 days
Explanation:
A’s 1-day = 1/10
A’s 4-day work = 4/10 = 2/5
Remaining = 3/5 done by (A + B) in 2 days
A + B = (3/5)/2 = 3/10 ⇒ B = 3/10 – 1/10 = 1/5 ⇒ 5 days
Q14. A and B can do a work in 15 days, and B alone can do it in 25 days. In how many days can A do it alone?
Ans: 37.5 days
Explanation:
A + B = 1/15, B = 1/25
A = 1/15 – 1/25 = (5 – 3)/75 = 2/75 ⇒ 37.5 days
Q15. A can complete a piece of work in 40 days, and B can do the same in 50 days. They work together for 10 days, then C completes the remaining work in 10 days. How long will C take alone?
Ans: 100 days
Explanation:
A + B = (1/40 + 1/50) = 9/200
Work in 10 days = 9/20
Remaining = 11/20
C = (11/20)/10 = 11/200 ⇒ 100 days
Q16. 8 men can finish a job in 12 days. After working 6 days, 4 men leave. How many more days will the remaining men take?
Ans: 12 days
Explanation:
8 × 12 = 96 man-days
Work done in 6 days = 8 × 6 = 48
Remaining = 48 man-days
Now 4 men left ⇒ 4 men remain
Days = 48/4 = 12 days
Q17. A can do a work in 18 days, B in 27 days. If they work together and earn ₹1350, how much should A get?
Ans: ₹810
Explanation:
A’s efficiency = 1/18, B’s = 1/27
Ratio = 3 : 2
A’s share = (3/5) × 1350 = ₹810
Q18. A can do a job in 15 days, B in 20 days, and C in 30 days. They work together for 2 days, then A leaves. In how many more days will B and C finish the rest?
Ans: 8 days
Explanation:
A + B + C = (1/15 + 1/20 + 1/30) = 1/6
Work in 2 days = 1/3
Remaining = 2/3
B + C = 1/20 + 1/30 = 1/12
Required = (2/3) ÷ (1/12) = 8 days
Q19. A and B together can do a work in 8 days. A is twice as efficient as B. In how many days can A alone complete it?
Ans: 12 days
Explanation:
A = 2x, B = x ⇒ A + B = 3x = 1/8 ⇒ x = 1/24 ⇒ A = 2/24 = 1/12 ⇒ 12 days
Q20. A, B, and C can do a work in 20, 30, and 60 days respectively. How long will they take together?
Ans: 10 days
Explanation:
1/20 + 1/30 + 1/60 = (3 + 2 + 1)/60 = 6/60 = 1/10 ⇒ 10 days
Time and Work Concepts for Bank Exams
Bank exams often frame logic-based or symbolic questions around Time and Work. These may involve indirect relations or require candidates to use mental calculation speed.
Example:
A can finish work in 16 days, B is 33.33% more efficient than A.
How many days will B take?
Ans: 12 days
Explanation: If A’s efficiency = 3 units/day, B = 4 units/day → Time = 48/4 = 12
What is Time and Work in Quantitative Aptitude?
Time and Work is a fundamental topic in Quantitative Aptitude that deals with measuring the efficiency of individuals or machines performing tasks over time. It builds upon concepts from ratio and proportion, unitary method, and LCM.
This topic is common in almost all competitive exams because it tests logical reasoning, speed, and the ability to manage complex calculations under time pressure.
Skills Required:
- Basic arithmetic (LCM, ratios, percentages)
- Logical sequencing
- Efficiency-based calculations
- Time-speed optimization
Read other Time and Work related blogs:
| Time and Work Practice Blogs | Exam-Specific Practice Blogs |
|---|---|
| Time and Work Questions for IBPS Exams | Data Interpretation Based on Time and Work |
| Time and Work Questions for SSC CHSL |
Why is Time and Work Important in Competitive Exams?
Understanding Time and Work helps candidates solve a wide range of real-life and exam-oriented problems involving jobs completed by people, machines, or groups in a given time.
| Exam | No. of Questions | Difficulty |
| SSC CGL / CHSL | 1-2 | Easy |
| IBPS PO / SBI PO | 1-2 | Moderate |
| RRB NTPC / Group D | 1 | Easy |
| State PSC / Police | 1-2 | Moderate |
Time and Work Quantitative Aptitude Short Notes
Some of the important notes aspirants must keep in mind while solving questions based on Time and Work are as follows:
| Term | Details |
| Work | The total task to be done (generally considered as 1 unit unless specified). |
| Efficiency | Amount of work done per unit of time. |
| Time | The duration taken to complete the work. |
| LCM Approach | Used to assume total work for simplifying calculations. |
| Work and Wages | Wages are distributed in the ratio of work done. |
| Alternate Work | Situations where different persons work on alternate days. |
Concepts Used in Time and Work Questions
The concepts used in Time and Work questions are as follows:
| Concept | Explanation |
| Basic Formula | Work = Rate × Time |
| Efficiency Comparison | More efficiency → Less time |
| Total Work | Often assumed as LCM of individual times |
| Combined Work | 1/A + 1/B for A and B working together |
| Negative Work | Used when a pipe/person does the opposite of the task (like leakage/draining) |
| One Day’s Work | 1/Total time to complete the job |
What are the Types of Time and Work Questions in Quantitative Aptitude?
Types of Time and Work questions commonly asked are as follows:
- Direct Time-Efficiency Problems: Basic questions using formula Work = Time × Efficiency
- Combined Work: Two or more persons working together or alternately
- Work and Wages: Wages divided in proportion to work done
- Pipes and Cisterns: Same logic applied to tanks filled/drained
- Inverse Problems: Work undone or uncompleted scenarios
Time and Work Formulas for Quantitative Aptitude
Use these formulas for rapid solving:
- Work = Time × Efficiency
- Efficiency = 1 / Time
- If A can do a work in ‘x’ days, B in ‘y’ days
→ Together = xyx+y\frac{xy}{x + y}x+yxy days - If total work = W, and A does ‘a’ work/day
→ Time = W / a - Wage Ratio = Work Ratio
- Alternate Day Work: Use LCM of days worked and alternate pattern tracking
Time and Work Tricks for SSC CGL and Other Exams
Some of the effective time and work question tricks are as follows:
- Assume total work as LCM of given days to simplify complex fractions
- Convert time into fractions (like 1/2 day = 0.5, etc.) for faster calculation
- Use unit work approach for one-day or one-hour work logic
- Avoid decimal calculations — work with ratios and LCM
- For pipes and cisterns, treat filling as +ve work, draining as –ve work
- Reverse engineer the question using options for time-bound mocks
- Break alternate day cycles into full and half cycles
Common Mistakes to Avoid while Solving Time and Work
While solving Time and Work problems in competitive exams, candidates often make avoidable mistakes that lead to incorrect answers.
- Ignoring unit conversions (e.g., hours to days) – Always align units before starting calculations.
- Not using the LCM method – Direct fractions can be slow; assuming total work as LCM simplifies the process.
- Assuming wrong total work – Always choose a multiple or LCM of given time durations to avoid errors.
- Confusing efficiency with speed – Efficiency refers to work/time, not to distance/time like speed.
- Misinterpreting draining/filling logic – Treat filling as positive work and draining as negative work, especially in pipe and cistern problems.
FAQs
Time = Work ÷ Efficiency.
Assume total work as the LCM of individual time durations.
Add their one-day work: 1/A + 1/B.
Use ratio-based comparison to divide work accordingly.
Find one-day work first, then multiply or divide to find total time or work.
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