Explanation:
the baking rate is
200/5 bagels/hour = 40 bagels/hour
now the question is about how many they can make in 17 hours ? the work is being done in the same ratio.
so, with 40 = 40/1 as basic bake ratio
40/1 × 17/17 = 40×17/17 = 680/17 bagels/hour.
always remember, when transforming a fraction (and a ratio is mathematically a fraction) while keeping the value unchanged, we need to multiply the numerator and the denominator by the same value (that way we overall simply multiply by 1).
they can bake 680 bagels in 17 hours with the basic rate of 40 bagels per hour.