Copy and complete each of the Diamond Problems below. The pattern used in the Diamond Problems is shown at right.

1. 

   Hint (a):

   Refer to problem 6-121 for help on this problem.

2. 

   Hint (b):

   Add $x$ and $y$ to fill the sum box. Multiply them to fill the product box.

3. 

   Hint (c):

   What times $0.2$ is equal to $2.6$?

   Answer (c):

   $y = 13$. Can you find the sum of $0.2$ and $13$?

4. 

   Hint (d):

   This problem is very similar to part (c).