Question

14. A and B can do a work in 12 days, B and C in 15 days, C and A in 20 days. If A, B and C work together, they will complete the work in : ​

Answer 1

Answer:

10 days

Step-by-step explanation:

According to question,

A and B can do a work in 12 days

∴ (A + B)’s one day’s work $latex = \frac{1}{12}&s=1$

Similarly, (B + C)’s one day’s work $latex = \frac{1}{15}&s=1$

and (C + A)’s one day’s work $latex = \frac{1}{20}&s=1$

On adding all three,

∴ 2 (A + B + C)’s one day’s work $latex = \frac{1}{12}+ \frac{1}{15}+ \frac{1}{20}&s=1$

$latex = \frac{10+8+6}{120} = \frac{1}{5}&s=1$

and (A + B + C)’s one day’s work $latex = \frac{1}{10}&s=1$

∴ A, B and C together can complete the work in 10 days.

Hope it helps you •

Answer 2

Answer:

5 days

Step-by-step explanation:

they will complete the work in 5 days

1/12+1/15+1/20 = 12/60.

12/60, 1/5

answer is 5