Question

A car travelling at a constant speed takes $50$ seconds longer to travel a distance of $5$ miles than it would take to travel at $72$ miles per hour. What is the speed of the car?

• A. $40$
• B. $50$
• C. $60$
• D. $70$
• E. $80$

Answer 1

Answer: (C)

$60$

Time $=50$ seconds

Distance $=5$ miles

Speed $=72$ miles/hour

Therefore, time $=\frac{5}{72}$ seconds

$\frac{5}{72}\to 5$

$1\to 5\times \frac{72}{5}$

$\frac{50}{60}$ hour$\to 5\times \frac{72}{5}\times \frac{50}{60}=60$ miles/hour