Question

the person A can do a work in 5 days and person B can do it in 8 days . In how many days will they do it together ? ​

Answer 1

Answer:

1/8+1/5 = 1/x and the answer is 40/13

Answer 2

Given that A,B does the work in 8,4 days; if total work be x;

⇒ work done in 1 day by A, B is 

$\frac{x}{8}$

,

$\frac{x}{4}$

⇒ if they both work for one day then work done will be 

⇒ 

$\frac{x}{8}$

+

$\frac{x}{4}$

=

$\frac{3x}{8}$

⇒ Then total work done x will take 

$\frac{8}{3}$

=

$2 \times \frac{2}{3}$

 days .... (using proportions.)