SOLUTION: An athlete can burn 10 calories per minute while running and 4 calories per minute while walking. If the athlete burns 450 calories in 60 minutes, how long is spent on each activi
Question 572741: An athlete can burn 10 calories per minute while running and 4 calories per minute while walking. If the athlete burns 450 calories in 60 minutes, how long is spent on each activity? Answer by mathsmiles(68) (Show Source):
You can put this solution on YOUR website! This athlete trains for 60 minutes. Some of those minutes are spent walking and some are spent running.
X minutes he spends running. The rest of the hour (60-X) minutes he spends walking.
If he burns 10 cals per minute running then his total calories running are
10 cals/min times X minutes.
If he burns 4 cals per minute walking then his total calories walking are 4 cals/min times (60-X) minutes.
All together he burns 450 calories.
Put these 3 statements together and we have
10X + 4(60-X) = 450
10X + 240 - 4X = 450. Subtract 240 from each side of the equation ...
10X - 4X = 210. Combining like X terms ...
6X = 210. Dividing both sides by 6 ...
X = 35 minutes
He spends 35 minutes running and 60-35 = 25 minutes walking.
Let's check our answer:
10 cals/min times 35 minutes = 350 calories.
4 cals/min times 25 minutes = 100 calories.
Adding them gives us 450 calories. Check!
