Question

Drew burned 1,800 calories Friday playing 1 hour of basketball and canoeing for 2 hours. On Saturday, he spent 2 hours playing basketball and 3 hours canoeing and burned 3,200 calories. How many calories did he burn per hour when playing basketball?

Answer 1

He burn 1000 calories per hour when playing basketball

Explanation:

Let x be the no. of calories burnt per hour while playing Basketball

Let y be the no. of calories burnt per hour while canoeing

We are given that Drew burned 1,800 calories Friday playing 1 hour of basketball and canoeing for 2 hours.

So, Equation becomes =
`x+2y = 1800` --- A

On Saturday, he spent 2 hours playing basketball and 3 hours canoeing and burned 3,200 calories.

So, Equation becomes =
`2x+3y = 3200` --- B

Plot A and B

`x+2y = 1800` ---- Black

`2x+3y = 3200` --- Red

Refer the attached figure

Intersection point gives the solution

(x,y)=(1000,400)

So, he burn 1000 calories per hour when playing basketball

Answer 2

He burnt 1000 calories per hour when playing basketball.

Explanation:

Let B be calories burned playing basketball, and C calories burned canoing.

1800 = B + 2C

3200 = 2B + 3C

From 1st equatipn, we get that B = 1800 - 2C

Replacing into the 2nd equation, we have:

3200 = 2(1800-2C) + 3C

3200 = 3600 - 4C + 3C

3200 = 3600 - 1C

C = 3600 - 3200

C = 400

Knowing C, we find B.

B = 1800 - 2C = 1800 - 2*400 = 1800 - 800 = 1000 calories.