Billy likes to go cycling
his bike has wheels of diameter 80cm
he invented a counter for his bike, which counts how many revolutions the wheel does
one day the counter shows 170 revolutions
how far has billy cycled to the nearest meter

We know that the diameter of the wheel is 80cm. Thus we can find the circumference of the wheel by the equation C=2(pi)r or, knowing that the Diameter is 2r, C=D(pi).

Now, we know that the circumference of the wheel is 80(pi)cm.

If the wheel rotates 170 times, that means we multiply the circumference of the wheel by 170 to receive the answer.

80 x 170 x pi = about 42725.66cm

we then can divide our answer by 100 to convert to meters -->
(42725.66cm)(1m/100cm) = 427.2566 which we round to 427m

Hope this helped!

About 25of the grand parents will spend less than two hours a day online

Do you need with the x value for the minimum? its always between the two intercepts for a parabola