Jack usually mows his lawn in three hours. Marilyn can mow the same yard in 5 hours. How much time would it take for them to mow the lawn together?
Jack --> 1/3 yard/hr
Marilyn --> 1/5 yard/hr
together 1/3+1/5 = 5/15+3/15 = 8/15 yard/hr
so 15/8 hr/yard
15/8 hr/yard * 60 min/hr = 112.5 min = 1 hr 52 1/2 minutes
To find out how much time it would take for Jack and Marilyn to mow the lawn together, we need to calculate their combined mowing rate.
First, let's determine Jack's mowing rate. We are given that Jack usually mows the lawn in 3 hours. So, his mowing rate is 1/3 of the lawn per hour.
Next, let's determine Marilyn's mowing rate. We are given that Marilyn can mow the same yard in 5 hours. So, her mowing rate is 1/5 of the lawn per hour.
To calculate their combined mowing rate, we need to add their individual rates together:
1/3 + 1/5 = 5/15 + 3/15 = 8/15
Therefore, Jack and Marilyn can mow 8/15 of the lawn per hour together.
To find out how much time it would take for them to mow the entire lawn together, we can use the formula:
Time = 1 / combined mowing rate
Plugging in the combined mowing rate, we have:
Time = 1 / (8/15)
Time = 15/8
So it would take Jack and Marilyn 15/8 hours to mow the lawn together, which is equivalent to 1 hour and 52.5 minutes.