Question

Jorge has saved $250 in four months. Express his rate of savings as a unit rate.?

A. $125 every two months

B. $62.50 every month

C. $60 every month

D. $500 every eight months

Answer 1

`($62.50)/("1 month")color(white)("d")larr" Unit rate"`

Option B

Explanation:

`color(blue)("Explaining unit rate")`

Basically this means 'for 1 of' something.

Example: miles per hour, say; `-> (60" miles")/(1" hour") ->` 60 mph

So the bottom number of a `color(red)("ratio")` needs to be changed to 1.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(blue)("Answering the question")`

Given: `$250` in 4 months

The time span is months. So unit months will be: 1 month.

Expressing what is given as a fraction:

We have $250 per 4 months `->($250)/("4 months")`

But we need 1 month.

`-> color(white)("ddd") ($250->4)/("4 months"-:4) color(blue)(= ($62.5)/("1 month")color(white)("d")larr" Unit rate")`