Branch red and green out
Red: 7/10
Green: 3/10
On the red branch R and G
R: 6/9
G: 3/9
Why is the 9 there is because it minus off from the first brach causing the number to be 10-1=9
Why in R is 6? (Because its also -1)
But why G is not deducted? (Because the first branch doesn’t have green as it is red)
For the green branch R and G branch out again
R: 7/9
G: 2/9
So the probability of both that are red is:
P(both is red) = 7/10 x 6/9 (refer to legend)