Question

Suppose that 12 inches of wire costs 36 cents.

At the same rate, how much (in cents) will 7 inches of wire cost?

Answer 1

The cost of 7 inches of wire is 21 cents.

Explanation:

The problem can be solved using the unitary method.

The unitary method is a process of solving a problem by first determining the value of the single unit and then multiplying this value to compute the required quantity.

Or, unitary method can be used to determine the value of a unit from the multiple or a multiple from the unit.

It is provided that 12 inches of wire costs 36 cents.

Then, 1 inch of wire will cost,
`[(36)/(12)] = 3 cents`

So, 7 inches of wire will cost,
`3*7=21cents`

Thus, the cost of 7 inches of wire is 21 cents.