Question

A car's speedometer has a percent error of 5%. The speedometer currently shows that the car is traveling at a speed of 60 mph.

Which statement describes what the actual speed of the car could be?


The actual speed of the car is either 30 mph or 90 mph.

The actual speed of the car is either 55 mph or 65 mph.

The actual speed of the car is either 57 mph or 63 mph.

The actual speed of the car is either 58 mph or 62 mph.

Answer 1

The actual speed of the car is either 57 mph or 63 mph.

Explanation:

because i took the test

Answer 2

The actual speed of the car is either 57 mph or 63 mph

Explanation:

Given as :

The measured speed o the car = 60 mph

The percentage error in speedometer = 5 %

Let The actual speed of car = x mph

Now, percentage error =
`(\textrm actual value - \textrm measured value)/(\textrm measured value)` × 100

So,
`(5)/(100)` =
`(x - 60)/(60)`

or,
`(5)/(100)` × 60 = x - 60

Or, 3 = x - 60

∴ x = 63 mph

Hence The actual speed of the car is either 57 mph or 63 mph . Answer