Question

Jack usually mows his lawn in 6 hours. marilyn can mow the same yard in 4 hours. How much time would it take for them to mow the lawn together?

Answer 1

Answer:

2.4 hours or 2 hours and 24 minutes

Step-by-step explanation:

Jack mows 1/6 of the lawn per hour while Marilyn mows 1/4 of the lawn together. Adding up those rates yields in their combined mowing rate:

$R = \frac{1}{6}+ \frac{1}{4}\\R=\frac{10}{24}$

The time required for them to mow the entire lawn is:

$t = \frac{1}{R}\\t = \frac{1*24}{10}\\ t=2.4\ hours$

It would take them both 2.4 hours to mow the lawn together.