Answer:
7 hours
Explanation:
For yard work:
He earns $24 for 3 hours of yard work, which means he earns $8 per hour.
For babysitting:
He earns $48 for 4 hours of babysitting, which means he earns $12 per hour.
Now, you can calculate how long it takes to earn $168 with each of these rates:
Time for yardwork = $168 ÷ $8 per hour = 21 hours
Time for babysitting = $168 ÷ $12 per hour = 14 hours
To find out how much longer it will take Leroy to earn the money if he only does yard work, you can subtract the time for yardwork from the time for babysitting:
Time difference = Time for babysitting - Time for yardwork = 14 hours - 21 hours = -7 hours
Since the time difference is negative, it means that he will take 7 hours less to earn the money if he only does yardwork for his grandmother compared to babysitting.