Question

an assembly line worker at Rob's Bicycle factory adds a seat to a bicycle at the rate of 2 seats in 11 minutes. Write a proportion relating the number of seats s to the number of minutes m. At this rate, how long will it take to add 16 seats? 19 seats?

Answer 1

Rate = 2 seats/11 minutes = 2/11  seats/min

Therefore the time required for s seats is
$(m \, min) = \frac{s \, seats}{ \frac{2}{11} \, \frac{seats}{min} } = \frac{11s}{2} \, min$
That is,
m = (11s)/2 min

When s = 16, obtain
$m = \frac{11(16)}{2} = 88 \, min$

When s = 19, obtain
$m = \frac{11(19)}{2} = 104.5 \, min$

Answers:
$m = \frac{11s}{2}$
When s = 16, m = 88 min
When s = 19,  m = 104.5 min