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 4 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?​

+25 = x

step-by-step explanation:

here x is the hypotenuse of a right triangle whose legs are 7 and 24.   by the pythagorean theorem, 7² + 24² must equal x²:

x² = 49 + 576 = 625.   thus, x = +√625 = +25 = x

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.