Question

Travis was walking to school when hesaw some friends walking a block aheadof him. After running to catch up with hisfriends, his heart was beating 24 beatsevery 10 seconds. At this rate, how manytimes would his heart beat in 3 minutes?

Answer 1

his heart would beat 432 times in 3 minutes

Step-by-step explanation

we can easily solve this by using a rule of three,

then

Step 1

to do that we need the same measure unit for the time, let's use seconds

so, we need to convert 3 minutes into seconds,

the equivalence is

`1\text{ minute = 60 seconds}`

hence, to convert from minutes into seconds just mutlply by 60

then

`3\text{ minutes}\Rightarrow3\cdot60\text{ seconds=180 seconds}`

Step 2

now, let's make the proportion

let x represents the number of times his heart would be in 180 seconds( 3 minutes)

so

`\begin{gathered} \text{if} \\ 24\text{ beats}\Rightarrow10\text{ s} \\ \text{then} \\ x\text{ beats}\Rightarrow180\text{ s} \end{gathered}`

so, the proportion is

`\begin{gathered} \frac{24\text{ beats}}{10\text{ s}}=\frac{x}{180\text{ s}} \\ (24)/(10)=(x)/(180) \\ \end{gathered}`

finally, to solve for x multiply both sides by of the equation by 180 and reduce

`\begin{gathered} (24)/(10)=(x)/(180) \\ (24)/(10)\cdot180=(x)/(180)\cdot180 \\ (4320)/(10)=x \\ 432=x \end{gathered}`

therefore, his heart would beat 432 times in 3 minutes

I hope this helps you