Question

Solve question no . 13

Answer 1

Answer:

30 days

Step-by-step explanation:

(i) Work done by (A + B) in 1-day = (1/12).

(ii) Work done by (B + C) in 1-day = (1/15)

(iii) Work done by (C + A) in 1-day = (1/20)

On adding (i),(ii),(iii), we get

2(A + B + C)'s 1-day work = (1/12) + (1/15) + (1/20)

                                         = (5 + 4 + 3)/60

                                         = 1/5

∴ (A + B + C)'s 1-day work = 1/10.

A's 1-day work = (1/10) - (1/15)

                        = (3 - 2)/30

                        = 1/30.

Therefore,A alone can complete the work in 30 days.

Hope it helps!

Answer 2

Step-by-step explanation:

(A + B) in 1-day = (1/12).

(B + C) in 1-day = (1/15)

C + A) in 1-day = (1/20)

2(A + B + C)'s 1-day work = (1/12) + (1/15) + (1/20)

= (5 + 4 + 3)/60

= 1/5

(A + B + C)'s 1-day work = 1/10.

A's 1-day work = (1/10) - (1/15)

= (3 - 2)/30

= 1/30.