Question

Three oranges cost $1.35. At this rate, how much do 5 oranges cost?

Answer 1

If 3 oranges cost $1.35, we have a ratio of orange to price of:

`r=(3)/(1.35)`

The ratio for 5 oragens and a price "x", is:

`r=(5)/(x)`

If both have the same ratio, we can equalize them:

`\begin{gathered} (3)/(1.35)=(5)/(x) \\ 3x=5\cdot1.35 \\ 3x=6.75 \\ x=(6.75)/(3) \\ x=2.25 \end{gathered}`

So, at this ratio, 5 oranges will cost $2.25.