Question

A and b can do a work in 60 days; b and c can do it in 120 days; a and c can do it in 80 days. in what time a alone can do the work?

Answer 1

13 days will carry to do work alone

Answer 2

Answer:

A alone can do the work is 96 days.

Step-by-step explanation:

it is given that A and B can do a work in 60 days; B and C can do it in 120 days; A and C can do it in 80 days.

One day work done A and B is $\frac{1}{60}$.

$A+B=\frac{1}{60}$             .... (1)

One day work done B and C is $\frac{1}{120}$.

$B+C=\frac{1}{120}$          ....(2)

Subtract (1) and (2).

$A+B-(B+C)=\frac{1}{60}-\frac{1}{120}$

$A-C=\frac{1}{120}$                  ....(3)

One day work done A and C is $\frac{1}{80}$.

$A+C=\frac{1}{80}$                     ....(4)

Add equation (3) and (4).

$2A=\frac{1}{120}+\frac{1}{80}$

$2A=\frac{2+3}{240}$

$2A=\frac{5}{240}$

$2A=\frac{1}{48}$

Divide both sides by 2.

$A=\frac{1}{96}$

One day work of A is $\frac{1}{96}$.

Therefore A alone can do the work is 96 days.