Question

A alone and B alone can do a work in respectively 18 and 8 days more than both working together. Find the number of days required if both work together.

Answer 1

Hey Mate


your answer is ----


Given,

A work alone = 18 days

B work alone = 8days


therefore, both work together in

[(18×8 (/(18+8) ] days

= 144/26

= 5.5 days


Hence, A & B work done together in 5 and 1/2 of one days



Hope it helps you

Answer 2

Time and Work

Let A and B can do a work together in x days.

Therefore , A will do that work alone in $(x+18)\ days$.

B will do that work alone in $\ (x+8) \ days$.

According to question,

$\frac{1}{x+18}+ \frac{1}{x+8}= \frac{1}{x} \\\\\implies \frac{x+18+x+8}{x^2+26x+144} =\frac{1}{x} \\\\\implies x(2x+26)=x^2+26x+144\\\\\implies 2x^2+26x=x^2+26x+144\\\\\implies x^2=144\\\\\implies x=12$

So, if they work together , it will be completed in 12 days.