EXPLANATION
Given the facts:
Blue marble = 8
Yellow = 2
Green = 10
Red=4
The probability of choosing a blue marble without a replacement will be given by the formula:
P(x) = Number of incomes / Total number of possible outcomes
Replacing terms:
P (blue) = 8 / (8+2+10+4) = 8/24
The answer is A. 8/24