Question

Steve drives $80$ miles in $2$ hours in his car. If he drives at the same speed, how many hours will he take to drive $320$ miles?

• A. $8h$
• B. $20h$
• C. $10h$
• D. $16h$

Answer 1

The correct option is A $8h$

Time taken to drive $80mi=2h$
Unit rate = distance covered in unit time $=\frac{\text{distance traveled}}{\text{time taken}}=\frac{80}{2}=40\text{mi per h}$
Thus, $320mi$ can be covered in $=\frac{320}{40}=8h$
Alternate solution:
Let it take $x$ hours to travel $320$ miles. Then, we can write
$80:2=320:x$
$\Rightarrow \frac{80}{2}=\frac{320}{x}$
By cross multiplication,
$\Rightarrow 80x=320\times 2$
$\Rightarrow 80x=640$
$\Rightarrow x=\frac{640}{80}=8h$
Thus, Steve will take 8 h to drive $320mi.$