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?
a) 4.5 hours; julia 9 hours
b) 7.5 hours; julia 15 hours
c) 4.5 hours; julia 2.25 hours
d) 0.5 hours; julia 1 hours

The answer is:

The correct option is:

A) Jeff, 4.5 hours; Julia 9 hours.

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.

Hence, the correct option is:

A) Jeff, 4.5 hours; Julia 9 hours.

Have a nice day!

A

Step-by-step explanation: