Question

it takes 4 hours for Andrew to repair his car, Ben can do the same in 6 hours, how many hours dose it take for them to do it if they are working together?

Answer 1

rate of time taken by andrew=1/4

rate of time taken by ben=1/6

rate of time taken by both of them=(1/4+1/6)

=5/12hours

Answer 2

Answer:

12/5 Hours

Step-by-step explanation:

According to the question

Time is taken by Andrew to repair his car = 4 hours

Time is taken by Ben to repair Andrew's car = 6 hours

We have to find out LCM for both 4 and 6 hours

that will be 12

=12 units of work

work done by Andrew in 1 hour =12/4=3 Units

work done by Ben in 1 hour=12/6=2 Units

work done by both Andrew and Ben in 1 hour= 3 +2 =5 units

so time taken by both Andrew and Ben to repair the car = total work/work done by both Andrew and Ben in 1 hour

=12/5

ans will be 12/5 hours