Correct answers only !
a person changed the size of the wheels on his motorcycle
he changed the size from a tire that had a 25 inch diameter to a tire that has a 28 inch diameter. he didn’t realize this would affect his speedometer and odometer. he didn’t re-calibrate either after changing the wheel size.
how fast is he really going on the new tires when his speedometer reads 60 mph?
a. 54 mph
b. 75 mph
c. 67 mph
d. 70 mph

  C. 67 mph

Step-by-step explanation:

The speedometer reports speed based on the number of revolutions the tire makes in a given time period. If the motorcycle travels 28/25 times as far on each revolution, its speed is 28/25 times as great.

  (28/25)(60 mph) = 67.2 mph ≈ 67 mph

The distance traveled is proportional to the circumference of the tire, which is proportional to the diameter. Hence, actual speed for a given speedometer reading is proportional to the diameter of the tire.

12/11c

or

12

c

11