Bart burns 200 calories in 0.75 hour of kayaking. How many calories does he burn in a 3-hour kayaking trip?

Mar 4, 2018

Bart burns $800$ calories in his three-hour trip.

Explanation:

Bart burns $200$ calories in $0.75 ,$ or $\frac{3}{4} ,$ hours.

Let's simplify this ratio of $200 : \frac{3}{4}$ so we can see how many calories Bart burns in one hour. This will require multiplying both sides of the ratio by $\frac{4}{3} :$

$200 \left(\frac{4}{3}\right) : \frac{\cancel{3}}{\cancel{4}} \cdot \frac{\cancel{4}}{\cancel{3}}$

We end up with $\frac{800}{3} : 1$, meaning that every hour, $\frac{800}{3}$ calories are burned.

We now need an equation.

Let's denote the calories Bart burns by $C .$

Furthermore, let's denote hours kayaked by $h .$

$C = \frac{800}{3} h$ where $h$

Plugging in $3$ for $h ,$ we get

$C = \left(\frac{800}{\cancel{3}}\right) \left(\cancel{3}\right) = 800$

Bart burns $800$ calories in his three-hour trip.