Question

A car travels 126 miles in 3 hours. At this rate, how many miles can the car travel in 4 hours?

A
168

B
94.5

C
42

D
10.5

Answer 1

A. 168

Explanation:

`\bold{METHOD\ 1:}\\\\\begin{array}{ccc}126\ mi&-&3h\\\\x\ mi&-&4h\end{array}\qquad\text{cross multiply}\\\\3x=(126)(4)\\3x=504\qquad\text{divide both sides by 3}\\x=168\ mi`

`\bold{METHOD\ 2:}\\\\126\ mi\ \text{in}\ 3\ h,\ \text{then}\ (126\ mi)/(3)=42\ mi\ \text{in}\ 1\ h.\\\\\text{If}\ 42\ mi\ \text{in}\ 1\ h,\ \text{then}\ (42\ mi)(4)=168\ mi\ \text{in}\ 4h.`