Question

A and B can do a job in 6 days, B and C in 9 days, and A and C in 12 days. How much time
will they take to complete the job if they all work together? How long will each of them take
to do the job?​

Answer 1

Answer:

$\frac{72}{13}$ days

Step-by-step explanation:

Let us give the job a value of 1.

A and B require 6 days to finish the job

⇒A and B finish  $\frac{1}{6}$ of the job in 1 day.

A + B = $\frac{1}{6}$

Similarly we can say that,

B + C =  $\frac{1}{9}$ and

A + C = $\frac{1}{12}$

Adding all of these,

A + B + B + C + C + A = $\frac{1}{6}$ +  $\frac{1}{9}$ +$\frac{1}{12}$

2A + 2B + 2C = $\frac{6+4+3}{36}$

2(A + B + C) = $\frac{13}{36}$

A + B + C = $\frac{13}{72}$

Therefore, they can complete the work in $\frac{72}{13}$ days.

Answer 2

Answer:

Is this question from the book "Essential ICSE Mathematics for Class 8"?

Step-by-step explanation:

Bcoz I am also having the same book as I am from Class-8.