a bag contains 4 blue marbles,6 red marbles, 10 yellow marbles and 6 green marbles.What is the probability of not drawing a red marble?

Answer 1

number of "not reds" is 20
so prob(not red) 20/26 = 10/13

or

prob(red) = 6/26 = 3/13
prob(not red) = 1 - 3/13 = 10/13