Question

A person's heartbeat is 71 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.

Answer 1

First step: identify how many heart beats in a year.

To determine the heart beats in a year multiply the heart beats in a minute with
`(60* 24* 365)` years.

Thus, heart beats in a year comes out to be =
`71 * (60* 24* 365) years`

=
`37317600` heart beats in a year

Heart beats
`3.1* 10^(9)` in a life time.

Thus, number of years he lives is calculated by the division of heart beats in a year and heart beats in a life time.

Number of years he lives =
`(3.1* 10^(9))/(37317600)`

=
`8.3* 10^(-8)* 10^(9)`

=
`8.3* 10`

=
`83.0` years

Thus, number of years he lives is
`83.0` years