Answer:
It take the helper 6 Hours to mow the lawn by himself
Step-by-step explanation:
Given:
Time Taken by the landscaper to mow the land = 2 hours
Time Taken When the landscaper works with a helper = 1.5 hours
To Find :
Time Taken by the helper to mow the lawn by himself
Solution:
The General formula is
[tex]\frac{1}{X} + \frac{1}{Y} = \frac{1}{Z}[/tex]
where
X is time taken by the landscaper
Y is the time taken by the helper
Z is Time Taken by both the landscaper and the helper together.
Substituting the values
[tex]\frac{1}{2} + \frac{1}{Y} = \frac{1}{1.5}[/tex]
[tex]\frac{1}{1.5} - \frac{1}{2} = \frac{1}{Y}[/tex]
By cross multiplication
[tex]\frac{(2-1.5)}{(1.5 \times 2)} = \frac{1}{Y}[/tex]
Now,
[tex]Y = \frac{3.0}{0.5}[/tex]
Y = 6
