Question

If you're driving one and a half miles per minute, slow down by $15$ miles per hour, and then reduce your speed by one third, how fast are you going now?

Answer 1

Finding the speed:

The initial speed $=1.5$mile per minute

$$\begin{gathered} =1.5\times 60 \\ =90mph \end{gathered}$$

If it slow down by $15mph$then reduces speed be

$$\begin{gathered} =90-15 \\ =75mph \end{gathered}$$

Then reduces by one third $=\frac{1}{3}\times 75=25$

Therefore, the required speed is $75-25=50mph$.