Question

P, Q and R can do a work together in 20 days.
A and B can do the same work at double the
speed. If all of them work together, in how many
days will they finish
th of the work?​

Answer 1

Answer:

just recipocal all the values and add them equals to whatever days or time..you may able to get ans

Answer 2

If all of them work together, it will take $6\dfrac{2}{3}$ days to finish the work.

Explanation:

Let the group of P, Q and R  be denoted as Group X and the group of A and B is denoted as group Y.

The time taken by Group X  to do the job =$t_1=$ 20 days

The time taken by Group Y  to do the job =$t_2=$ $\dfrac{20}{2}$ = 10 days

Now , when both groups will combine and work together then the total time taken by all of them will be:

$t=\dfrac{t_1t_2}{t_1+t_2}\\\\=\dfrac{20\times10}{20+10}=\dfrac{200}{30}=\dfrac{20}{3}=6\dfrac{2}{3}\ days$

Hence, If all of them work together, it will take $6\dfrac{2}{3}$ days to finish the work.

# Learn more :

12 men can complete a work in 18 days. Six days after they started working, 4 more men joined them. How many days will all of them together complete the remaining work?

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