The probability of rolling a 5 on a six-sided number cube is 1/6. What is the probability of not rolling a 5 on a six-
sided number cube? Express your answer as a fraction.

Step-by-step explanation:

Event of not rolling a 5= {1,2,3,4,6}

P(not rolling a 5) = 5/6

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.