a. 9
b. 12
c. 12
There are 3 thirds in 1 whole.
There are 9 thirds in 3 wholes.
If 3 is 1/3, the whole is 9.
There are 4 fourths in 1 whole.
There are 12 fourths in 3 wholes.
If 3 is 1/4, the whole is 12.
There are 3 thirds in 1 whole.
There are 12 thirds in 4 wholes.
If 4 is 1/3, the whole is 12.