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)
15x=1000 you get x=1000/15 which is approximately 67
The answer is B. The angle next to 100 degrees would be 80 as the angles are supplementary. Then you would add 80 + 70 = 150. All the angles in a triangle add to 180, thus making the "x" angle 30 due to 180 - 150.
Hope this helped :))