Question

Rakhi can do a piece of work in 15 hours while Rashmi can do it in 12 hours. How long will both take to do it
working together
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Answer 1

Question :-

Rakhi can do a piece of work in 15 hours while Rashmi can do it in 12 hours. How long will both take to do it working together ?

Answer :-

Given :

• Rakhi's 1 hour's work = 1/15
• Rashmi's 1 hour's work =1/12

Solution :-

↪Both's 1 hour's work

= 1/15+1/12

= 9/60

↪let both take to do it in t hours

= (9/60)t

= 1

★ t = 60/9h = 6h + (6×60)/9min

★ t = 6hour and 40 minute

• 6 hour and 40 minute both take to do it working together

Answer 2

Answer:

6.667 hours (6 hours 40 minutes)

Step-by-step explanation:

If Rakhi can do the piece of work in 15 hours, then she will complete 1/15 work in an hour.

In the same way, Rashmi will complete 1/12 work in an hour.

So, if they work together, they will complete 1/15 + 1/12 work in an hour

1/15 + 1/12 = 4/60 + 5/60

=9/60 work will get completed in an hour

if 9/60 work is completed in an hour, then 60/9 hours will be taken to complete the work

60/9 = 6.667

So, 6.667 hours or 6 hours 40 minutes will be taken to complete the work