Question

After An Exercise, Ali and Ben measured their heart rates. Thre ratio of their heart rates was 15:17. Bens heart rate beat 18 more times than Ali. calculate Ali's heart rate.​

Answer 1

Answer: 135

Explanation:

Let heart rate of Ali and Ben be x and y

Their ratio was 15:17 which means

$\frac{x}{y} = \frac{15}{17} \Rightarrow \frac{y}{x} = \frac{17}{15} \Rightarrow y = \frac{17x}{15}$

Also Ben's heart rate is 18 more than Ali, which means

$y = x+18$

But,

$y = \frac{17x}{15}$

Therefore,

$x+18=\frac{17x}{15}$

$\Rightarrow \frac{17x}{15} - x = 18$

$\Rightarrow \frac{17x-15x}{15} = \frac{2x}{15} = 18$

$\Rightarrow x=\frac{18\times15}{2} = 15\times9 = 135$

Hope this helped. Take care :)