Question

Four balls are simultaneously picked at random from a jar containing 2 red balls, 2 green balls, and 6 yellow balls.
What is the probability that exactly two of the selected balls will be red?

Answer 1

Using combination symbols,
prob = C(2,2)/C(10,2) = 1/45

or

prob = (2/10)(1/9) = 2/90 = 1/45

Answer 2

it just says how many red balls are there