Question

If 5 kilos of Black Label cheddar cheese cost $24.80, what does 8 kilos of cheese cost?Make sure you round to the hundredths place since your answer is money.

Answer 1

This is a problem of proportions , were we know what a relationship between two quantities is, and want to find the relationship that is equivalent to it.

So we start saying that $24.80 is to 5 kilos, the same as some unknown price (let's call it "x") is to 8 kilos.

In math terms this is written as:

24.80 : 5 the same as (=) x : 8

which can also be written using fractions:

`(24.80)/(5)=(x)/(8)`

Notice that in the above expression, we can solve for the unknown "x" (that means isolate x on one side of the equal sign) by multiplying both sides of the equation by the factor "8" thus cancelling the denominator on the right and leaving x on its own on that side of the equal sign:

`x=(24.80\cdot8)/(5)=39.68`

So we see that the price we are looking for is $39.68 (for the 8 kilos of the cheese)