I'm gonna send you a picture because it'll explain the answer better
8^15 ÷ 1/8^3 = 8^15 x 8^3=8^18
SQUARES BECAUSE THEY ARE IN THE MIDDLE DUMMY
Get them to have a common denominator so you can add them
(1/3)×2= 2/6 and (1/2)×3= 3/6
Add them together
(2/6)+ (3/6)= 5/6
So 5/6 of the class planted either marigolds or tulips and 1/6 of the class planted neither