Chapter 6, Problem 17MCQ

To determine

To write: The equation that relates number of beats to the number of minutes.

Answer to Problem 17MCQ

The equation that compares the blue whale`s heart beats to the number of minutes is $n=9t$ . And total required heart beats in 20 minutes be 180 times.

Explanation of Solution

Given information: 

The blue whale`s heart beats 45 times in 5 minutes.

Concept used:

First to calculate rate of heart beat by calculating total number of times heart beats per minute. Then, use the formula,

Total heart beats $=\text{rate}\times \text{total}\text{minutes}$

Calculation:

Total heart beats in one minutes = rate of heart beat $=\frac{45}{5}=9$ times.

Now using above formula, if the total heart beats are represented by n and total minutes by t , then equation that compares heart beats to the number of minutes be

  $n=9t$

Now when total minutes be 20 or when $t=20$ , then,

  $n=9\times 20=180$

Required equation is $n=9t$ and heart beats 180 times in 20 minutes.