math
posted by kyle .
while riding her bike, jennifer burns 450 calories every 1/2 hour. Based on this rate, how many calories will jennifer burn if she rides her bike for 1 3/4 of an hour?

First, multiply 450 by 2, which is 900 calories for one hour. Now, for the 3/4, set up a proportion.
.50 / 450 = .75 / ?
450 X .75 = 337.5
337.5 / .50 = 675.
So, Jennifer will burn 675 calories every 3/4 of an hour.
900 + 675 = 1575, the number of calories Jennifer will burn if she rides her bike for 1 3/4 hours.