Question

Bag contains 4 yellow blocks, 6 white ,7 green. If 2 blocks are pulled from bag what is the probability that they will both be green

Answer 1

Total number of blocks = 4 + 6 + 7 = 17

number of green blocks = 7

Number of ways to pick first green block = 7 because there are 7 green block

So, favourable outcome = 7 and total outcome = 17

Thus, probability of picking first green block = 7/17

Similarly, Number of ways to pick second green block = 6 because one green block is picked and only 6 left

So, favourable outcome = 6 and total outcome = 16(becuase one green block is already picked, now remaining only 16 block)

Thus, probability of picking second green block = 6/16

So, total probability = probability of picking first green block * probability of picking second green block

setting the values, we get

total probability = (7/17)*(6/16) = 42/272 or 21/136 or 0.1544 (rounded to 4 decimals)