SSC CGL Time and Work Practice Test 27

1. A can complete a work in 18 days and B in 24 days. Working together, they finish the work in:

• A. 72/7 days (Correct)
• B. 80/7 days
• C. 84/7 days
• D. 90/7 days

Explanation: Combined rate = 1/18 + 1/24 = 7/72. Time = 72/7 days.

2. A and B can finish a work in 20 days. They work together for 8 days, then A leaves. B completes the remaining work in 18 days. In how many days can B alone finish the work?

• A. 28 days
• B. 30 days (Correct)
• C. 32 days
• D. 36 days

Explanation: In 8 days, 8/20 = 2/5 work is done. Remaining 3/5 is done by B in 18 days, so B's full time = 18 x 5/3 = 30 days.

3. A is 50% more efficient than B. If B completes a job in 30 days, A will complete it in:

• A. 18 days
• B. 20 days (Correct)
• C. 22 days
• D. 24 days

Explanation: A's efficiency is 1.5 times B's, so A's time = 30/1.5 = 20 days.

4. 12 men can complete a work in 15 days. How many men are required to complete the same work in 9 days?

• A. 18
• B. 20 (Correct)
• C. 22
• D. 24

Explanation: Men x days is constant. Required men = 12 x 15 / 9 = 20.

5. A pipe fills a tank in 12 hours and another fills it in 18 hours. Together they fill the tank in:

• A. 36/5 hours (Correct)
• B. 40/5 hours
• C. 42/5 hours
• D. 45/5 hours

Explanation: Combined rate = 1/12 + 1/18 = 5/36. Time = 36/5 hours.

6. A pipe fills a tank in 10 hours, while a leak empties it in 15 hours. If both are open, the tank will fill in:

• A. 20 hours
• B. 25 hours
• C. 30 hours (Correct)
• D. 35 hours

Explanation: Net rate = 1/10 - 1/15 = 1/30, so time = 30 hours.

7. A, B and C can complete a work in 12, 18 and 36 days respectively. If total wages are Rs. 3,300, B's share is:

• A. Rs. 800
• B. Rs. 900
• C. Rs. 1,000
• D. Rs. 1,100 (Correct)

Explanation: Efficiency ratio = 1/12:1/18:1/36 = 3:2:1. B gets 2/6 of 3300 = 1100.

8. A can do a work in 10 days and B in 15 days. They work on alternate days, starting with A. In how many days will the work be completed?

• A. 11 days
• B. 12 days (Correct)
• C. 13 days
• D. 14 days

Explanation: In 2 days they complete 1/10 + 1/15 = 1/6 work. In 10 days, 5/6 work is done. On day 11 A does 1/10, leaving 1/15, which B completes on day 12.

9. A can complete a job in 25 days. What fraction of work does A complete in 5 days?

• A. 1/6
• B. 1/5 (Correct)
• C. 1/4
• D. 1/3

Explanation: Work done in 5 days = 5/25 = 1/5.

10. 16 workers can finish a work in 24 days. After 6 days, 4 workers leave. How many more days are needed?

• A. 21
• B. 22
• C. 23
• D. 24 (Correct)

Explanation: Total work = 16 x 24 = 384 worker-days. Work done = 16 x 6 = 96. Remaining = 288. With 12 workers, time = 288/12 = 24 days.

11. A and B complete a work together in 16 days. If A alone takes 24 days, B alone will take:

• A. 36 days
• B. 40 days
• C. 44 days
• D. 48 days (Correct)

Explanation: B's rate = 1/16 - 1/24 = 1/48, so B takes 48 days.

12. Two pipes fill a tank in 8 hours and 12 hours. A third pipe empties it in 24 hours. If all are opened together, the tank fills in:

• A. 4 hours
• B. 5 hours
• C. 6 hours (Correct)
• D. 7 hours

Explanation: Net rate = 1/8 + 1/12 - 1/24 = 1/6, so time = 6 hours.

13. The efficiencies of A and B are in the ratio 4:5. If A takes 25 days, B will take:

• A. 18 days
• B. 20 days (Correct)
• C. 22 days
• D. 24 days

Explanation: Time is inversely proportional to efficiency. B's time = 25 x 4/5 = 20 days.

14. A can do 2/5 of a work in 8 days. How many days will A take to complete the whole work?

• A. 16 days
• B. 18 days
• C. 20 days (Correct)
• D. 22 days

Explanation: If 2/5 work takes 8 days, full work takes 8 x 5/2 = 20 days.

15. A, B and C can finish a work in 30, 40 and 60 days respectively. They work together for 5 days. What fraction of work remains?

• A. 1/2
• B. 7/12
• C. 5/8 (Correct)
• D. 2/3

Explanation: Combined rate = 1/30 + 1/40 + 1/60 = 3/40. In 5 days, work done = 15/40 = 3/8, so remaining work = 5/8.