Q: Alex has 2 cakes that are each cut into 8 slices. A fourth of the slices are given away to his friends. A third of the remaining slices are given away to his family. Alex eats 3 slices. How many slices of the cake are left?
A: There are 2 * 8 = 16 slices of cake. There are 16 / 4 = 4 slices. There are 16 - 4 = 12 slices left. There are 12 / 3 = 4 slices given away. There are 12 - 4 - 3 = 5 slices of cake left. The answer is 5.

Q: Marla has a grid of squares that has 10 rows and 15 squares in each row. She colors 4 rows of 6 squares in the middle of the grid with red. She colors all squares on the first 2 and last 2 rows with blue. Then she colors the rest with green. How many squares does Marla color green?
A: There are 10 x 15 = 150 squares in a grid. 4 x 6 = 24 squares are colored red. There are 2 + 2 = 4 rows that are all blue. Thus, a total of 4 x 15 = 60 squares are colored blue. 24 + 60 = 84 squares are color red or blue. Therefore, 150 - 84 = 66 square are green. The answer is 66.

Q: In Professor Plum's biology class there are 40 students. Of those students, 80 percent have puppies. Of those who have puppies, 25% also have parrots. How many students have both puppies and parrots?
A:
We start with the initial numbers of students, 40 and multiply that by .8 for 40 * 0.8 = 32 who own puppies. That the number of students with puppies, 32, and multiply that by .25 to find out how many own both puppies and parrots, 32 * 0.25 = 8 who own puppies and parrots. The answer is 8. The answer is 8.