Question

Brian rides his bike for 7.5 miles. The diameter of his bicycle tires is 20 inches. Estimate the

Answer 1

Answer:

7500 revolutions

Step-by-step explanation:

1 rotation of his bicycle tires is equivalent to 1 circumference in linear distance.

circumference = π*diameter = π*20 = 62.8 in

If 1 foot is equivalent to 12 inches, then 62.8 in are equivalent to:

1 ft / x ft = 12 in / 62.8 in

x = 62.8/12 = 5.2 ft

If 5280 ft are equivalent to 1 mile, then 5.2 ft are equivalent to:

5280 ft / 5.2 ft = 1 mile / x mile

x = 5.2/5280 = 0.001 mile

So, when 1 revolution is made, 0.001 mile had been travelled. To compute the number of revolutions after 7.5 miles are travelled, the following proportion must be satisfied:

1 revolution / x revolutions =  0.001 mile / 7.5 miles

x = 7.5/0.001 = 7500 revolutions