Question

Your friend's heart beats 18 times in 15 seconds when at rest. While running, your friend's heart beats 25 times in 10 seconds.

Answer 1

Answer:

Part A

1. 72 beats per minute

2. 150 beats per minute

Part B

1. 234 more times

Step-by-step explanation:

Part A:

1.

We can setup a simple ratio to solve for this problem.

Heart beats 18 times in 15 seconds, so heart beats x times in 60 seconds (1 min = 60 sec)

$\frac{18}{15}=\frac{x}{60}\\18*60=15x\\1080=15x\\x=\frac{1080}{15}=72$

At rest, heart rate is 72 beats per minute

Part A:

2.

We can do the same when running.

Heart beats 25 imes in 10 seconds, so heart beats x times in 60 seconds (1 min = 60 sec)

$\frac{25}{10}=\frac{x}{60}\\25*60=10x\\1500=10x\\x=\frac{1500}{10}=150$

While running, the heart rate is 150 beats per minute

Part B:

While running, heart beats 150 times per minute. So in 3 minutes, heart beats 150 * 3 = 450 times

While at rest, heart beats 72 times per minute. So in 3 minutes, heart beats 72 * 3 = 216 times

So the difference is  450 - 216 = 234 times more