Question

A human heart pumps about $7\times {10}^{-2}$ liter of blood per heartbeat. The average human heart beats about $72$ times per minute. How many liters of blood does a heart pump in $1$ year? $70$ years?

Answer 1

A human heart pumps about $7\times {10}^{-2}$ a litre of blood per heartbeat.

The average human heart beats about $72$ times per minute.

The number of litres blood pump in one-minute $=72\times 7\times {10}^{-2}$litres

$=504\times {10}^{-2}$litres
$=5.04$ litres

The number of litres blood pump in one-hour $=5.04\times 60$ litres

The number of litres blood pump in $24$ hours $=5.04\times 60\times 24$ litres

The number of litres blood pump in $365$ days $=5.04\times 60\times 24\times 365$ litres

The number of litres blood pump in $1$ year $=2,649,024$ litres

The number of litres blood pump in $70$ year $=2,649,024\times 70$ litres

$=185,431,680$ litres

$=1.85\times {10}^8$ litres