P(r/w) is the probability of picking a red rose at first picking and a white rose at second picking.
P(w/r) is the probability of picking a white rose at first picking and a red rose at second picking.
P(r/w) =

×

=

P(w/r) =

×

=

Notice that the second fraction is out of 18 because the second picking of rose will be out of 18 since the first rose is not replaced.
P(r/w) equals to P(w/r)
I wrote some notes please read and if you not sure contact me
Step One
Solve for CE as a numerical value
CE = 1/2 * CD = 1/2 66 = 33
CE = 33
Step Two
Solve for x
CD also equals x^2 - 3 which is given.
x^2 - 3 = 33 Add 3 to both sides
x^2 = 33 + 3
x^2 = 36 Take the square root of both sides
sqrt(x^2) = sqrt(36)
x = 6
Step 3
Find the length of AE
AE is given as 6x - 10
x = 6
AE = 6*6 - 10
AE = 36 - 10
AE = 26
Step 4
Find AB
AE = 1/2 AB Definition of bisect
26 = 1/2 AB Multiply by 2
2*26 = AB
AB = 52 <<<<<<<<Answer