Probability of drawing a red ball:
Total number of balls = 2 + 18 = 20
number of red balls = 2
number of green balls = 18
total number of favourble outcomes = 2
probability = number of favourable outcomes/number of total outcomes.
= 2/20 = 1/10
Therefore probability of drawing a red ball is 1/10.
Probability of drawing a green ball:
total number of balls = 2 + 18 = 20
number of green balls = 18
number of red balls = 2
total number of favorable outcomes = 18
probability = number of favourable outcomes/number of total outcomes.
= 18/20 = 9/10
Therefore probability of drawing a green ball is 9/10.