A car mechanic tested the accuracy of three speedometers. The table shows the speed registered by each of the three speedometers. The actual speed each speedometer was tested on was 90 kmph.


Which statements are true?


Speedometer Speed displayed (kmph)

A 92

B 87

C 88


Choose exactly two answers that are correct.


A.

Speedometer A and Speedometer C had the same percent error.


B.

Speedometer C had the least percent error.


C.

Speedometer C had a 0.02% error.


D.

Speedometer B had about a 3.3% error.

Verified Answer :

A: We know that A is correct because both speedometers A & C had the same percentage error (2.2%) as they were both incorrect by 2km/h.

D: Speedometer B did have an error of 3.3%, we can check this by dividing 87/90= 0.967 (3dp), which becomes 3.3%.