Question

★★★ 6. on the average your heart beats about 72 times per minute. at this rate, about how many times will it beat:
a. in a 30 - day month?
b. in a year?
c. in your lifetime, if you live to 72 years of age?

Explanation:

Part a: In a 30 - day month

Step 1: Find minutes in a day

There are 24 hours in a day and 60 minutes in an hour. So minutes in a day: $24\times60 = 1440$

Step 2: Find minutes in 30 days

Minutes in 30 days: $1440\times30=43200$

Step 3: Find heartbeats in 30 days

Heart beats 72 times per minute. So total beats: $72\times43200 = 3110400$

Step 1: Assume a year has 365 days (or use 366 for leap year, here we use 365)

Minutes in a day: $24\times60 = 1440$

Step 2: Minutes in a year

Minutes in 365 days: $1440\times365 = 525600$

Step 3: Heartbeats in a year

Total beats: $72\times525600=37843200$

Step 1: Use the result from part b (using 365 days a year for simplicity)

Heartbeats in one year: $37843200$

Step 2: Heartbeats in 72 years

Total beats: $37843200\times72 = 2724710400$

Answer:

$3110400$

Part b: In a year