Question

Bill can mow the lawn in 2 hours, and his younger brother Tom can now it in 3 hours. If both brothers mow the lawn together, how many hours will it take them?

Answer 1

If they both stop at 1/2 of the lawn, it would take them 1.5 hours to finish.

You can find this by finding how long it would take bill to mow the lawn and divide that time in half, and the same with tom.

Since Tom would take longer to finish his half, it can be assumed that Bill will stop once he reaches his half

Answer 2

It will take them 1.2 hours to mow the lawn together

How many hours will it take them to mow the lawn together

From the question, we have the following parameters that can be used in our computation:

Bill = 2 hours

Tom = 3 hours

Let the time it take to mow the lawn together be represented with x

So, we have

1/x = 1/2 + 1/3

Take the LCM and evaluate the fraction

1/x = (3 + 2)/6

1/x = 5/6

This means that

x = 6/5

Evaluate

x = 1.2

Hence. it will take them 1.2 hours to mow the lawn together