Question

A human heart beats an average of 80 beats per minute. How many heartbeats is this in 80 years?

• A. $3.36\times {10}^9$
• B. $3.24\times {10}^{10}$
• C. $2.48\times {10}^7$
• D. $5.76\times {10}^8$

Answer 1

The correct option is A $3.36\times {10}^9$

Number of times a heart beats in a minute = $80$

Number of times a heart beats in an hour = $80\times 60=4.8\times {10}^3$ beats

Number of times a heart beats in a day = $24\times 4.8\times {10}^3=1.152\times {10}^5$ beats

Number of times a heart beats in a year = $365\times 1.152\times {10}^5$ beats = $4.20\times {10}^7$ beats

So, number of times a heart beats in $80$ years = $80\times 4.20\times {10}^7=3.36\times {10}^9$ beats