We can think of this as an equality
5 Lawns = 8 Hours
If she needs 40 hours, you can multiply 8 hours by 5 to get 40, but now it's not balanced. So, you need to multiply 5 to the other side too so:
5 x (5) = 8 x (5)
Therefore she mows 25 Lawns in 40 Hours
By finding the rate of work, we will see that in 40 hours she can mow 25 lawns.
First, we define the rate of work as the quotient between the work done and the time in which it was done. Here we know that she mows 5 lawns in 8 hours, so the rate is:
R = (5 lawns)/(8 hours) = 0.625 lawns per hour.
Now, in 40 hours, she can mow 40 times the amount she mows in one hour, this is:
N = (0.625 lawns per hour)*40 hours = 25 lawns
In 40 hours she can mow 25 lawns.
If you want to learn more about rates, you can read:
https://brainly.com/question/8728504
