# MATH

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**P**
.

Many people are interested in losing weight through

exercise. An important fact to consider is that a person

needs to burn off 3,500 calories more than he or she takes

in to lose 1 pound, according to the American Dietetic

Association.

The following table shows the number of calories burned per hour (cal/h) for a variety

of activities, where the figures are based on a 150-pound person.

Activity Cal/h Activity Cal/h

Bicycling 6 mi/h 240 Running 10 mi/h 1,280

Bicycling 12 mi/h 410 Swimming 25 yd/min 275

Cross-country skiing 700 Swimming 50 yd/min 500

Jogging 5 mi/h 740 Tennis (singles) 400

Jogging 7 mi/h 920 Walking 2 mi/h 240

Jumping rope 750 Walking 3 mi/h 320

Running in place 650 Walking 4 mi/h 440

Work with your group members to solve the following problems. You may find that

setting up proportions is helpful.

For problems 1 through 4, assume a 150-pound person.

1.If a person jogs at a rate of 5 1/2mi/h for 3 1/2h in a week, how many calories do they

burn?=2590 cal.

2.If a person runs in place for 15 minutes, how many calories will be burned?=162.5 cal.

3.If a person cross-country skis for 35 minutes,how many calories will be

burned?=431.6 cal

4.How many hours would a person have to jump rope in order to lose 1 pound? (Assume

calorie consumption is just enough to maintain weight, with no activity.)=4 hr and 20 min

5.Heavier people burn more calories (for the same activity), and lighter people burn

fewer. In fact, you can calculate similar figures for burning calories by setting up the

appropriate proportion.At what rate would a 120-pound person burn calories while bicycling at 12 mi/h?=328 cal per hr.

6.At what rate would a 180-pound person burn calories while bicycling at 12 mi/h?=492 cal per hr

7.How many hours of jogging at 5 1/2 mi/h would be needed for a 200-pound person to

lose 5 pounds? (Again, assume calorie consumption is just enough to maintain weight,

with no activity.)=17.74 hrs