Question

A bag contain 10 counters of which 7 are green and 3 are white.A counter is picked at random from the bag and its colour is noted. The counter is not replaced. A second counter is then picked out. Find the probability that
a) The first counter is green
b)The first counter is green and the second counter is white
c) the counter are of different colour​

Answer 1

Answer:

a) 0.7

b) 0.2333

c) 0.4666

Step-by-step explanation:

a) 7 out of 10 marbles in the bag are green, so when choosing out of 10 marbles, there is a 7/10 chance that it will be green.

b) Use the probability from part a and multiply it by the probability of choosing a white marble out of 9 (because one of the marbles has been removed). This can be written as 7/10 x 3/9, which is 0.2333.

c) Use the probability from part b and add it to the probability of choosing a white marble first and then a green marble. This can be written as (7/10 x 3/9) + (3/10 x 7/9), which is 0.4666.

Answer 2

Answer:

See below

Step-by-step explanation:

a) 7/10

b) 7/10 x 3/9 = 21/90 = 7/30

c) Also 7/30