Andrea has 2 cakes. each of her friends eats 2/3 of a cake. how many servings does andrea have?

There are several important information's already given in the question. Based on those given information's the answer to the question can be easily deduced.
Number of cakes that Andrea has = 2
Amount of cake each of her friends eat = 2/3
Let us assume the number of friends that Andrea has = x
Then
(2/3) * x = 2
2x/3 = 2
2x = 2 * 3
2x = 6
x = 6/2
  = 3
So we can say from the above deduction that Andrea has 3 friends and this makes 3 servings also. I hope the procedure is clear enough for you to understand.

1935/10,000= 387/2000the answer to the question is c