Question

By working together, A and B can finish a work in
15 days. If B alone can finish the work in 20 days,
in how many days can A alone finish the work?​

Answer 1

Answer:

60 Days

Step-by-step explanation:

(A + B)’s 1 day’s work = \frac{1}{15}

B’s 1 day’s work = \frac{1}{20}

∴ A’s 1 day’s work = \frac{1}{15}-\frac{1}{20} = \frac{4-3}{60}= \frac{1}{60}

∴ A alone will do the work in 60 days.

Answer 2

A and B together can complete the work in 15 days so, (A+B)'s one day work = 1/15

If A alone can complete the work in 20 days then A's one day work = 1/20

Let B alone can complete the work in x days so B's one day work = 1/x

Now,

(A+B)'s one day work = A's one day work + B's one day work

1/15 = 1/20+1/x

1/x = 1/15-1/20

1/x = 1/60

x = 60

Hence B alone can complete the work in 60 days.

Hope it helps you plz mark as brainiliest.