Question

On anne's bicycle, the ratio of pedal turns to rear-wheel turns in second gear is 4 to 7. if her rear wheel turns 875 times per mile,how many times does she turn the pedal in one mile?hint:set up and solve as a propportion to find x.

Answer 1

Let the number of times she turns the pedal in one mile be x.

Given that her rear miles turns 875 times in one mile and the ratio of pedal turns to rear wheel turns is 4 to 7, then

$\frac{4}{7} = \frac{x}{875} \\ \\ \Rightarrow 7x=4(875)=3,500 \\ \\ \Rightarrow x= \frac{3,500}{7} =\bold{500}$

Therefore, she turns the pedal 500 times in one mile.

Answer 2

4 pedal turns (PT) = 7 rear-wheel turns (RT) RT=4PT/7 If RT = 875 xPT = 875RT substituting RT as 4PT/7 xPT = 875*4PT/7 x = 500 Therefore she needs to turn the pedal 500 times to 875 rear-wheel turns in one mile.