The circumference of the top of the cake is
in.
It sounds like the baker is trying to line the circumference with cherriesto fit as many as possible along the border, like in the picture I've attached below.
This comes down to dividing the cake's circumference by the diameter of each cherry:

or about 39 cherries, making the answer D.
Answer:
I don't know what you mean with a b c d and e, but x=7
Step-by-step explanation:
x=7 because first you subtract 6 from each side, because you wan't to have just x, so you will get 3x=21, and then you just divide both sides by3 to get x=7
15. 5 times 3 is 15.
If you check, 15 divided by 3 is 5(red cars).