There are 9 counters in a bag.
7 of the counters are green.
2 of the counters are blue.
Ria takes at random two counters from the bag.
Work out the probability that Ria takes one counter of each colour.
You must show your working.

Please show the full working out so I know how to get full marks in future I’ll give brainiest

Respuesta :

Answer:

7/18

Step-by-step explanation:

Probability is the ratio of the number of possible outcomes to the number of total outcomes.

Given that there are 9 counters in a bag, 7 are green while 2 are blue.

the probability of picking at random a

Green counter = 7/9

Blue counter = 2/9

The probability that Ria takes one counter of each colour if 2 counter are picked as random is Green and Blue or Blue and Green

This is

=7/9 * 2/8 + 2/9 * 7/8

Recall that when a counter is picked the number of that ball available reduces and so does the total number of counter

=14/72 + 14/72

= 28/72

= 7/18