Question

A machine produces 440 bolts in 48 minutes. At the same rate, how many bolts would be produced in 30 minutes?

Answer 1

The units you want is $\frac{bolts}{min}$, so you set up the following equation:
$\frac{440\ bolts}{48\ mins} = \frac{x}{30\ mins} \\ 440*30=48*x\\ 13200=48x\\ x=\frac{13200}{48}=275 \frac{bolts}{min}$