Question

didi takes her pulse for 20 sec and counts 27 beats. how many beats per minute is this? the rate of didis pulse is beats per minute.

Explanation:

Step1: Set up proportion

We know 1 minute = 60 seconds. Let $x$ be the number of beats per minute. The proportion is $\frac{27}{20}=\frac{x}{60}$.

Step2: Cross - multiply

$20x = 27\times60$.

Step3: Solve for $x$

$x=\frac{27\times60}{20}=\frac{1620}{20}=81$.

Answer:

81