Answer:
38 miles
Step-by-step explanation:
Given,
The speed of Doreen = 9 miles per hour,
Since,
[tex]Speed = \frac{Distance}{Time}\implies Distance = Speed\times Time[/tex]
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
[tex]\implies \frac{90}{100}\times \text{ Irana's speed}=9[/tex]
[tex]\implies \text{Irana's speed}=\frac{900}{90}=10\text{ miles per hour}[/tex],
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
