A can do a work in 21 days and B in 29 days. In how many days will they complete 75% of the work together? MCQ with Answer and Explanation

A can do a work in 21 days and B in 29 days. In how many days will they complete 75% of the work together?
A. 11.63
B. 16.63
C. 9.13
D. 14.13
Answer: Option C
Solution (By JKSSB Mock Tests)
Combined time for full work multiplied by 0.75 = 9.13 days.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Time and Work Questions

Question #1
A can do a piece of work in 10 days and B can do the same work in 15 days. If they work together on alternate days starting with A, in how many days will the work be completed?
A. 12 days
B. 10 days
C. 11 days
D. 13 days

Correct Answer: Option A


Explanation:
Total work = LCM(10, 15) = 30 units. Efficiency of A = 3, B = 2. In a 2-day cycle (A then B), work done = 3 + 2 = 5 units. Number of cycles required to complete 30 units = 30 / 5 = 6 cycles. Total days = 6 * 2 = 12 days.

This question belongs to: Maths Time and Work
Question #2
A can complete a work in 15 days and B in 30 days. After working together for 5 days, what percentage of work remains?
A. 50.0
B. 57.5
C. 52.5
D. 55.0

Correct Answer: Option A


Explanation:
Remaining work = (1 - 5*(1/15+1/30))×100 = 50.0%.

This question belongs to: Maths Time and Work
Question #3
A can finish a work in 15 days and B in 25 days. They start together but B leaves 5 days before the completion of the work. Find the total number of days taken to complete the work.
A. 11.25 days
B. 13.25 days
C. 10 days
D. 12.5 days

Correct Answer: Option A


Explanation:
Total work = LCM(15, 25) = 75 units. Efficiency of A = 5, B = 3. Let total days be x. A works for x days, B works for (x - 5) days. 5x + 3(x - 5) = 75 => 8x - 15 = 75 => 8x = 90 => x = 90/8 = 11.25 days.

This question belongs to: Maths Time and Work