Answer:
r = 42
Step-by-step explanation:
0.85
total samples cases = 20
chances that are even or odd prime are 17 chances
2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20
probability = 17/20
= 0.85
-4 + -7= -11
When adding negative numbers if the are both negative then you add them. When you have a negative and a positive you subtract. In this problem they just took out the plus sign.