A can finish a task in 45 days and B can finish the same task in 30 da

1.	A can finish a task in 45 days and B can finish the same task in 30 days. They work together for 3 days and then A leaves. In how many days will B finish the remaining task?1. 52. 183. 254. 20
Answer» Correct Answer - Option 3 : 25 Given: A can finish a task in 45 days B can finish the same task in 30 days (A + B) work together for 3 days. Concept used: If a person does work in 'n' days, then one day work will be (1/n) part of the total work. Calculation: A's one day work = 1/45 part of the total work B's one day work = 1/30 part of the total work Worked by both for one day's work = (1/45) + (1/30) ⇒ (2 + 3)/90 ⇒ 5/90 ⇒ 1/18 part of the total work. Now Worked by them for 3 days = (1/18) × 3 ⇒ 1/6 part of the total work Now remaining work = 1 - (1/6) ⇒ (6 - 1)/6 ⇒ 5/6 part of the total work But B completes a work = 30 days The remaining work (5/6) part will be completed by B = (30) × (5/6) ⇒ 5 × 5 ⇒ 25 days. ∴ The remaining work, B will finish in 25 days.

A can finish a task in 45 days and B can finish the same task in 30 days. They work together for 3 days and then A leaves. In how many days will B finish the remaining task?1. 52. 183. 254. 20

Answer» Correct Answer - Option 3 : 25

Given:

A can finish a task in 45 days

B can finish the same task in 30 days

(A + B) work together for 3 days.

Concept used:

If a person does work in 'n' days, then one day work will be (1/n) part of the total work.

Calculation:

A's one day work = 1/45 part of the total work

B's one day work = 1/30 part of the total work

Worked by both for one day's work = (1/45) + (1/30)

⇒ (2 + 3)/90

⇒ 5/90

⇒ 1/18 part of the total work.

Now Worked by them for 3 days = (1/18) × 3

⇒ 1/6 part of the total work

Now remaining work = 1 - (1/6)

⇒ (6 - 1)/6

⇒ 5/6 part of the total work

But B completes a work = 30 days

The remaining work (5/6) part will be completed by B = (30) × (5/6)

⇒ 5 × 5

⇒ 25 days.

∴ The remaining work, B will finish in 25 days.