Mario can run 6 miles in 50 minutes. At this rate how many miles can he run in 30 minutes?

6/50 = x/30

180=50x

3.6=x

3.6 miles

Comment

You are not always obligated to change minutes to hours, especially in a question like this one where times are both given in minutes, and there are only 2 times given.

Givens

d1 = 6 miles

t1 = 50 minutes

r = ?

Equation and solution.

r = d1/t1

r = 6 / 50

r = 0.12 miles / minute. The rate is the same for the next part.

Part 2

Givens

t2 = 30 minutes

r = 0.12 miles/minute

d2 = ?

d = r * t2

d = 0.12 miles/minute * 30 minutes

d = 3.6 miles Note the minutes cancel.

Comment.

There is a quicker way of doing this. The two rates are the same, so you could create a proportion.

d1/t1 = d2/t2

d1 = 6 miles

t1 = 50 minutes

d2 = ?

t2 = 30 minutes

6/50 = d2/30 Cross miltiply

180 = 50 * d2 Divide by 50

180/50 = d2

3.6 = d2

Answer 3.6 miles