Question

An urn contains 6 green ball, 7 blue balls and 5 yellow balls. You are asked to draw 3 balls, one at a time (without replacement). Find the probability that a green is pulled first, then another green ball then a blue ball.

Answer 1

total number of balls= 6+7+5 = 18

we know

for first draw total outcome is 18 . number of green ball is 6 . so probabilty to take green ball in first draw is

for second draw total outcome becomes 17 (with out replacement) . here number of green ball will be 5 . so probability to take green ball in second draw is

for third draw , total outcome is 16 . number of blue ball is 7 . so probabilty to take blue ball in third draw is

so probablity for this complete drawing is

so answer is 0.043 .

if exact answer is needed then answer is fraction 35/816