Question

Question: 8
Mark for review
A and B can do a price of work in 12 days. B and C can do it in 15 days A and C can do it in 20 days. In how many days will A B and C finish it
working all together?​

Answer 1

SOLUTION:-

Given:

A & B can do a piece of work in 12 days.

B & C can do a piece of work in 15 days.

A & C can do a piece of work in 20 days.

To find:

How many days will A,B & C finish it working all together.

Solution:

A & B can do a piece of work in 12 days.

⚫(A+B)'s one day's work = 1/12

B&C can do a piece of work in 15 days.

⚫(B+C)'s one day's work= 1/15

A & C can do a piece of work in 20 days.

⚫(A+C)'s one day's work= 1/20

Now,

Adding all three:

Therefore,

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

$= > \frac{1}{12} + \frac{1}{15} + \frac{1}{20} \\ \\ = > \frac{5 + 4 + 3}{60} \\ \\ = > \frac{12}{60} \\ \\ = > \frac{1}{5}$

So,

(A+B+C)'s one day's work:

$= > 2(A+ B+ C) = \frac{1}{5} \\ \\ = > 10( A + B + C) = 1 \\ \\ = > (A + B + C) = \frac{1}{10}$

Therefore,

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

Hope it helps ☺️