A jar contains six red balls three green balls five white balls and seven yellow balls to balls are chosen from the jar with that with replacement what is the probability that both balls chosen are green

6+3+5+7 = 21 balls total

Choose 2 balls

21C2 = 210 total number of ways you could have chosen the two balls

(nCr - n=total, r=choose)

Total green balls = 3

You choose first green ball out of 3

3C1

Then you choose second green ball out of the 2 green balls left

2C1

Multiply these two outcomes

3C1•2C1 = 6

Probability=

6/210 = 1/35