Acar 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.

A and D. B is incorrect and is correct because both speedometer A and C are both the same distance away from the acceptable answer. For C and D you have to use a formula ([x-y]/x)*100. The brackets are used to represent absolute value and the one hundred is to make it percent. D is correct since x is 90 and y is 87 which makes
([90-87]/90)*100
(3/90)*100
0.033*100
3.3%

C is wrong because it has the percent sign when done as a percent it should come to 2.2%

e^-kt = n/n0 = 0.79  

-kt = ln 0.79  

t = - ln 0.79/0.0001  

= 2357 years

step-by-step explanation: