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:
[tex]R = \frac{1}{6}+ \frac{1}{4}\\R=\frac{10}{24}[/tex]
The time required for them to mow the entire lawn is:
[tex]t = \frac{1}{R}\\t = \frac{1*24}{10}\\ t=2.4\ hours[/tex]
It would take them both 2.4 hours to mow the lawn together.