‘A’ can do a work in 10 days and ‘B’ in 15 days. If they work on it together…
2023
‘A’ can do a work in 10 days and ‘B’ in 15 days. If they work on it together for 3 days, then the work that is left is :
- A.
10%
- B.
20%
- C.
40%
- D.
50%
Attempted by 76 students.
Show answer & explanation
Correct answer: D
Answer:
50%
Explanation:
Let the total work to be done is, say, 30 units.
A does the work in 10 days,
So A’s 1-day work = (30 / 10) = 3 units
B does the work in 15 days,
So B’s 1-day work = (30 / 15) = 2 units
Therefore, A’s and B’s together 1-day work = (3 + 2) = 5 units
In 3 days,
work done = 5 * 3 = 15 units
amount of work left = 30 – 15 = 15 units
Therefore the % of work left after 3 days = (15 / 30) * 100% = 50%