Question

Suppose that 24 inches of wire costs 96 cents.At the same rate, how much (in cents) will 21 inches of wire cost?

Answer 1

We are told that,

24 inches of wire costs 96 cents.

So, we could obtain the rate,

$\begin{gathered} 24\text{ inches = 96 cents} \\ 1\text{ inch = 4}cents \end{gathered}$

At this same rate, we can obtain the cost of 21 inches of wire,

21 inches of wire would cost;

$\begin{gathered} 21\times1inch=21\times\frac{96}{24}cents \\ 21\text{ inch= 84 cents} \end{gathered}$

Therefore, 21 inches of wire would cost 84 cents.