The question asks for the probability that a marble is NOT YELLOW
Total Marbles: orange+yellow+blue=7+3+2=12
We need to count all marbles except yellow:
orange+blue=7+2=9
Now to find the probability that is NOT YELLOW:
= 
Answer is 3/4
Hope it helps!
Answer:
is there a line that its perpendicular or parallel to?
Step-by-step explanation:
First, you need to distinguish if this is a permutation or a combination. The difference between the two is the order. In combination, order does not matter. Since there is no any restriction given, we assume this is a combination problem. The equation of determining the number of ways to choose 'r' objects out of total 'n' objects is:
Number of ways = n!/r!(n-r)! = 15!/3!(15-3)! = 455
There are 455 ways.