Aperson's heartbeat is 88 beats per minute. if his/her heart beats 3.1e9 times in a lifetime, how long (in whole years) does the person live? disregard leap years.

We can solve this problem by the rule of three.

88 beats1 minute
3.1*10⁹ beats    x

x=(3.1*10⁹ beats * 1 minute) / 88 beats=35227272.73 minutes.

Now, we express this amount of time in years.

1 year=365 days
365 days=365 day*(24 hour/1day)*(24 hour /1day)*(60 minutes /1hour)=
=525600 minutes.

525600 minutes1year
35227272.73 minutesx
 
x=(35227272.73 minutes * 1year) / 525600 minutes=67.0229 years
≈ 67 years.

this person can live 67 years.