Question

300 ml over 15 min is what rate of ml per hour

Answer 1

1200 ml per hour

Explanation:

To compute what rate is 300 ml over 15 mins as a rate of ml per hour, we do a rule of 3, using a variable x as that amount of ml we don't know yet. We should have everything in the same units, so instead of writing 1 hour we write 60 minutes:

`(300~ml)/(15~min)=(x~ml)/(60~mins)`

Now we solve for x:

`(300~ml)/(15~min)\cdot 60~mins=x~ml`

`(18000~ml)/(15) =x~ml`

`1200~ml =x~ml`

And so, now that we know the value of x, the rate we wanted to find is

`(1200~ml)/(60~mins)`

Which is just 1200 ml per hour.