Question

The diameter of a wheel of a car is 77 cm. How many revolutions will it make to cover 242 m? (Take π≈22/ 7)

Answer 1

Answer:  100 revolutions

This value is approximate because pi = 22/7 is approximate.

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Explanation:

Let's find the perimeter of the wheel, aka the circumference

C = pi*d

C = (22/7)*77

C = 242

The distance around the tire is approximately 242 cm

At first glance, it looks like one revolution will do the trick. However, we need to cover 242 meters and not 242 cm.

We can say the following

1 meter = 100 cm

242 meters = 24200 cm .... multiply both sides by 242

One revolution covers 242 cm, which is 1/100 of the distance we need to cover. So that means we need to do 100 revolutions to get to the target we're after.

1 revolution = 242 cm

100 revolutions = 24200 cm ... multiply both sides by 100

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We could also use a proportion to solve

(1 revolution)/(242 cm) = (x revolutions)/(24200 cm)

1/242 = x/24200

1*24200 = 242x

242x = 24200

x = 24200/242

x = 100