Question 1

C and D together can complete a work in 8 days. If C alone can do it in 12 days, in how many days can D alone complete the work?

Accepted Answer

Step 1: Combined rate (C + D) = 1/8 per day. Step 2: C's rate = 1/12 per day. Step 3: D's rate = 1/8 - 1/12 = (3 - 2)/24 = 1/24 per day. Step 4: D alone takes 24 days. Therefore, D takes 24 days.

Question 2

F and G together complete a work in 10 days. F alone can complete it in 15 days. How much work does G do in 1 day?

Accepted Answer

Step 1: Combined rate (F + G) = 1/10 per day. Step 2: F's rate = 1/15 per day. Step 3: G's rate = 1/10 - 1/15 = (3 - 2)/30 = 1/30 per day. Therefore, G completes 1/30 of the work in 1 day.

Question 3

E can do 1/4 of a work in 6 days. In how many days can E complete the entire work?

Accepted Answer

Step 1: E completes 1/4 work in 6 days. Step 2: For full work (4/4), days needed = 6 × 4 = 24 days. Therefore, E takes 24 days to complete the entire work.

Question 4

B can finish a task in 18 days. How many days will B take to complete 2/3 of the task?

Accepted Answer

Step 1: B's work rate = 1/18 per day. Step 2: To complete 2/3 of work, days needed = (2/3) ÷ (1/18) = (2/3) × 18 = 12 days. Therefore, B takes 12 days.

Question 5

B can finish a job in 15 days. In how many days can B finish 3/5 of the job?

Accepted Answer

Step 1: B's work rate = 1/15 per day. Step 2: To complete 3/5 of the work, time required = (3/5) ÷ (1/15) = (3/5) × 15 = 9 days. Therefore, the answer is 9 days.

Question 6

If 8 workers can build a wall in 15 days, how many days will 12 workers take to build the same wall, assuming all workers work at the same rate?

Accepted Answer

Step 1: Total work = 8 workers × 15 days = 120 worker-days. Step 2: With 12 workers, days needed = 120 worker-days ÷ 12 workers = 10 days. Therefore, answer is 10 days.

Question 7

E completes 1/4 of a work in 5 days. At this rate, how many days will E take to complete the entire work?

Accepted Answer

Step 1: E completes 1/4 work in 5 days. Step 2: Rate of E = (1/4) ÷ 5 = 1/20 per day. Step 3: Time to complete full work = 1 ÷ (1/20) = 20 days. Therefore, the answer is 20 days.

Question 8

A can complete a piece of work in 12 days. How much work will A complete in 5 days?

Accepted Answer

Step 1: A's work rate = 1/12 per day. Step 2: Work completed in 5 days = 5 × (1/12) = 5/12. Therefore, A completes 5/12 of the work.

CDS Basic Time & Work

Basic Time & Work — Practice Questions