A bag contains 3redballs,4blue balls 5white balls and 6black balls.a ball is picked at random what is the probability that it is either (a)blue,white or black with formula

Number of blue balls + Number of white balls + Number of black balls = 4 + 5 + 6 = 15

Total number of balls in the bag = 3 + 4 + 5 + 6 = 18

Probability = (Number of blue balls + Number of white balls + Number of black balls) / Total number of balls
Probability = 15 / 18
Probability = 5 / 6

Therefore, the probability that a ball picked at random is either blue, white, or black is 5/6.