Question

Brianna runs in the park every day at the average rate of b meters per minute. If Brianna runs double her regular speed for 15 minutes, what distance would she cover?

Answer 1

distance(15 min)=30b

Explanation

Step 1

Brianna runs in the park every day at the average rate of b meters per minute, it means for every minute she run b meters

$\text{rate}=b\frac{mt}{\min }$

then

distance= b (mt)

time=1 minute

rate= b mt per minute.

Step 2

now, 15 minutes she runs double her regular speed ( it is 2b)

time=15 minutes

then

time=15

rate=2b

$\begin{gathered} \text{rate}=\frac{dis\tan ce}{\text{time}} \\ 2b=\frac{dis\tan ce}{\text{time}} \\ 2b\cdot\text{time}=\text{distance}1 \\ 15\cdot2b=\text{ distance 1} \\ 30b=\text{distance 1} \end{gathered}$

Step 3

for the other 45 minutes, she runs at her regular rate (b)

time= 45 minutes=0.75 hours

rate=b

distance=distance2

$\begin{gathered} \text{rate}=\frac{dis\tan ce}{\text{time}} \\ \text{b}=\frac{dis\tan ce2}{45\text{ hours}} \\ \text{45}\cdot b=\text{distance 2} \end{gathered}$