Question

A grading machine can grade 48 multiple-choicetests in 1 minute. How long will it take themachine to grade 300 tests?

Answer 1

48 tests ----> 1 minute

300 tests --> x minutes

$\begin{gathered} 48\times x=300\times1 \\ 48x=300 \\ \frac{48x}{48}=\frac{300}{48} \\ x=\frac{25}{4}=6.25 \end{gathered}$

answer: 6.25 minutes