Question

During the summer holidays, your brother earns extra money mowing lawns. He mows 6 lawns an hour and has 21 lawns to mow. How long will it take him?

Answer 1

Answer:

His brother will take 3.5 hours or $3\frac{1}{2}$ hours to mow 21 lawns

Step-by-step explanation:

Given:

His brother mows 6 lawns in an hour.

To find the time his brother takes to mow 21 lawns.

Solution:

We will unitary method to find the time he will take to mow 21 lawns.

If 6 lawns are mowed in 1 hour

So, 1 lawn will me mowed in = $\frac{1}{6}$ hours.

Thus 21 lawns will be mowed in = $\frac{1}{6}\times 21=\frac{21}{6}=3.5$ hours.

Thus, his brother will take 3.5 hours or $3\frac{1}{2}$ hours to mow 21 lawns