Question

80 volunteers take a lie detector test to help police see how accurate this test is. If you pass the test, it means the test thinks you are telling the truth all the time. Of the volunteers, only 54 people will tell the truth at all times and the rest lie on purpose. The results show that 2 people who are supposed to lie pass the test and 7 people who are telling the truth fail the test. What was the accuracy of the test? % tyMaths_G....docx Type here to search V O Privacy and Legal Success stories I​

Answer 1

Answer: We see that 26 people must lie, and 2 of them passed making the fraction 2/80 doesn't work, then we see 7 people of the 54 failed the test, meaning another 7/80 which the sum equals 9/80. And since the percentage rate from 80 to 100 is 1.25, we multiply 9 and 1.25, to receive that the fail percent was 11.25, so the percent that was accurate was 88.75%. It is pretty confusing, but in time it will make sense.

Hope this helps.