Question

The water level of a lake fell by 1 1/4 in. during a 1 1/2 week long drought what is the average rate at which the water level changed every week

Answer 1

5/6 inches per week.

Explanation:

Answer 2

`(5)/(6)` inches per week

Explanation:

This is a very simple ratio problem. Basically,

If
`1(1)/(4)` inches in
`1(1)/(2)` week, then HOW MANY INCHES (let it be x) in 1 week???

We set up two ratios and cross multiply and solve for x:

`(1(1)/(4))/(1(1)/(2))=(x)/(1)\\1(1)/(4)*1=1(1)/(2)*x\\1(1)/(4)=1(1)/(2)x\\x=(1(1)/(4))/(1(1)/(2))\\x=((5)/(4))/((3)/(2))\\x=(5)/(4)*(2)/(3)\\x=(5)/(6)`

So average rate at which the water level changed every week is 5/6 inches per week.