Question

Jeff can weed the garden twice as fast as his sister Julia. Together they can weed the garden in 3 hours. How long would it take each of them working alone? Which of the following equations could be used to solve this problem?

Answer 1

Jeff, 4.5 hours; Julia 9 hours.

Explanation:

To solve the problem, we need to write two equations using the given information.

So, writing the first equation we have:

We know that Jeff can weed the garden twice as fas as his sister Julia, so:

Also, from the statement we know that they can weed the garden in 3 hours, so, writing the second equation we have:

Then, we need to substitute the first equation into the second equation in order to isolate Julia's rate, so, solving we have:

We have that Julia could weed the garden by herself in 9 hours.

So, calculating how long will it take to Jeff, we have:

We have that Jeff could weed the same garden by himself in 4.5 hours.

hope this helps!