Jack usually mows his lawn in 6 hours. Marilyn can mow the same lawn in 5 hours How much time would it take them to mow the lawn together?
In 30 hours, Jack mows 5 lawns, and Marilyn can mow 6 lawns.
That is 11 lawns in 30 hours.
rate=11/30 lawns/hr.
so one lawn will take 30/11 hrs.
Jack's rate = job/6
Marilyn's rate = job/5
their combined rate = job/6 + job/5
= 11job/30
job = rate x time
so time for combined effort = job/rate
= job/(11job/30)
= 30/11
So it takes 30/11 hours
= 2 8/11 hours
To find out how much time it would take Jack and Marilyn to mow the lawn together, we can use the concept of "work rates."
First, let's find out how much work each person can do in one hour. Jack can mow the lawn in 6 hours, so his work rate would be 1/6 of the lawn per hour. Similarly, Marilyn can mow the lawn in 5 hours, so her work rate would be 1/5 of the lawn per hour.
To find the combined work rate of Jack and Marilyn, we can add their individual work rates together. So, 1/6 + 1/5 = (5 + 6) / (5 * 6) = 11/30 of the lawn per hour.
Now, we can find out how much time it would take them to mow the whole lawn together by taking the reciprocal of their combined work rate:
1 / (11/30) = 30/11 ≈ 2.73 hours
Therefore, it would take Jack and Marilyn approximately 2.73 hours to mow the lawn together.