Answer:
Probability P(getting exactly 1 colour repeated twice) = 1/128
Step-by-step explanation:
Green ball=1, red ball = 1 , Blue ball=1 , yellow ball =1
Assuming the two colours are green balls
P(Green ball)= 1/4
P( green ball)= 1/4
P( blue ball)= 1/4
P(yellow or white)= 2/4
P(getting exactly 1 colour repeated twice)= 1/4 ×1/4 ×1/4 ×2/4 = 2/256 =1/128