If 815$ = 1 ounce. How many ounces are in 0.75$? Show work please

Question

It's a problem for one of my tests. I'm young so please don't judge :(

Answer 1

The best way to solve this is using conversion factors. We know 1 ounce = 815$, so we can use this as a conversion factor.

We want to convert 0.75$, so we have to start our conversion factor with this and after that we need our conversion factor to have $ on the denominator and ounces in the numerator:

 

0.75$*(1ounce/815$)= 0.75*1/815=  0.00092 ounces (the $ in the numerator and the denominator are canceled out)

Answer 2

A proportion can be used:

 

1 oz / $815 = x oz / $0.75   multiply both sides 0.75

0.75 / 815 = x                     divide

0.0009202453987730061 = x