Question

Doreen and Irena plan to leave their houses at the same time, roller blade towards each other, and meet for lunch after 2 hours on the road. Doreen can maintain a speed of 9 miles per hour, which is 90% of Irena's speed. If they meet exactly as planned, what is the distance between their houses?

Answer 1

Answer:

38 miles

Step-by-step explanation:

Given,

The speed of Doreen = 9 miles per hour,

Since,

$Speed = \frac{Distance}{Time}\implies Distance = Speed\times Time$

So, the distance covered by Doreen in 2 hours = 9 × 2 = 18 miles,

∵  Doreen speed is 90% of Irena's speed.

I.e. 90% of  Irana's speed = 9 miles per hour

$\implies \frac{90}{100}\times \text{ Irana's speed}=9$

$\implies \text{Irana's speed}=\frac{900}{90}=10\text{ miles per hour}$,

Thus, the distance covered by Irana in 2 hours = 10 × 2 = 20 miles

Hence,  the distance between their houses = distance covered by Doreen in 2 hours + distance covered by Irana in 2 hours

= 18 + 20

= 38 miles