If you want the answers, I'll give you the sol'ns. That way, your teacher won't be curious on how'd you get it:
1. [tex] \frac{1}{4} * 9 = \frac{9}{4} \\
[/tex]
2. [tex] \frac{3}{4} * 12 = 9 [/tex]
3. [tex]12 * \frac{1}{4} = 3 [/tex]
4. [tex]3 * \frac{2}{3} = 2[/tex]
Notice the numbers 2-4? I used cancellation because I wanted to keep the product in its lowest form.