Answer
One-fourth $\frac{1}{4}$ of the strip of beach can be cleared within one hour.
Work Step by Step
We are given that the entire strip of a beach can be cleared with 4 hours. So, if we divide the strip in 4 equal parts, then time taken should be one fourth of four hours: $\frac{1}{4}$(4) = 1 hour .
Thus in one hour, one fourth of the strip of the beach can be cleared up.