SOLUTION: I'm having trouble solving circumference ratios. The question is.... A boy rides his bicycle around a circular track that has a diameter of 76 ft. If a wheel of the bicycle spin

Algebra.Com
Question 5754: I'm having trouble solving circumference ratios. The question is....
A boy rides his bicycle around a circular track that has a diameter of 76 ft. If a wheel of the bicycle spins exactly 48 times when going once around the track, what is the diameter of the wheel?
Write your answer in inches.
The answer key gives this formula to follow: n=D3.14/d3.14 =D/d
And here are the steps they made, but I don't know why they multiplied 76 by 12.
n=48
D=76=76*12=912
d=912/48=19
d=19inches

Found 2 solutions by Abbey, cleomenius:
Answer by Abbey(339)   (Show Source): You can put this solution on YOUR website!
You have to have the same measurements when solving word problems.
in order to convert 76 feet into inches, we multiply by 12 (12 inches per foot)

Answer by cleomenius(959)   (Show Source): You can put this solution on YOUR website!
First step I did was find the convert to inches the diameter of the track.
76 * 12 = 912
Next, find the length of the track.
3.14 * 912 = 2865
Next, divide the distance by the number of revolutions of the wheel.
59.7
This is the distance traveled by one revolution of the wheel.
This distance = pi * the diameter of the wheel.
59.7 / pi = 19 inches for the diameter of the wheel.
The reason they multiplied by 12 is to have the calculations of the equation put into inches instead of feet.

RELATED QUESTIONS

5. A circular track has an inner circumference of 220 m.If the width of the... (answered by Alan3354)
Sammy took his dog running. Sammy and his dog ran 2 laps around a circular track near his (answered by solver91311)
The inner circumference of a circular track is 242m. The track is uniformly 7 m wide.... (answered by josgarithmetic)
Pls help me solve this question. A school boy rides a bicycle along the street to his... (answered by Alan3354)
if a circular track has an area of 314 ft squared, how many feet is twice around the... (answered by math-vortex)
the circumference of a circular track is 15.4m . find the diameter of the... (answered by gracia143)
Ri rides his bicycle to school every day.The diameter of his bicycle wheel is 70 cm when... (answered by checkley71)
a runner runs around a circular track with a circumference of 100 meters, what is the... (answered by Alan3354)
The radius of a circular cycle track 42 meters, how many kilometer will a cyclist cover... (answered by TimothyLamb)