Question

Nora earns $12 per hour. Convert $12 per hour to cents per minute.

Answer 1

We have to convert $12 per hour to cents per minute.

The easiest way to do that is to multiply the quantity by unit ratios.

We know that 1 dollar = 100 cents and that 1 hour = 60 minutes, so the expressions (1 dollar / 100 cents) and (1 hour / 60 min) are equal to 1 and do not affect the quantity if we multiply it by them (NOTE: will not change the quantity but will change the units).

For this example we can apply them like this:

`12\frac{\text{ dollars}}{\text{ hour}}\cdot(\frac{1\text{ hour}}{60\text{ min}})\cdot(\frac{100\text{ cents}}{1\text{ dollar}})=12\cdot(100)/(60)\frac{\text{ cents}}{\min }=20\frac{\text{ cents}}{\min}`

Answer: 20 cents per minute.