It will take Levi's dad 1.67 hours to wash the car alone.
Step-by-step explanation:
Time taken by Levi to wash car alone = 2.5 hours
Time taken by Levi and his father together = 1 hour
Let,
x be the time taken by Levi's dad.
Levi will contribute 1/2.5 hours and his dad will contribute 1/x to wash the car together.
[tex]\frac{1}{2.5}+\frac{1}{x}=1\\\\\frac{x+2.5}{2.5x}=1\\\\x+2.5=2.5x\\\\2.5=2.5x-x\\\\2.5=1.5x\\\\1.5x=2.5[/tex]
Dividing both sides by 1.5
[tex]\frac{1.5x}{1.5}=\frac{2.5}{1.5}\\x=1.67[/tex]
It will take Levi's dad 1.67 hours to wash the car alone.
