For N it is 2 since you multiply 4 times 2= 8, 2 times 2=4
8-4=4
1. 3 foot
2. 4 yard
3. 1 yard
4. 4 foot
5. 6 foot
6. 108 inch
7. 7.5 foot
8. 66 inch
9. 216 inch
10. 36 foot
11. 3.75 foot
12. 30 yard
Yes it is true! it is true because two different numbers go to the same number, if it was false it would have to be the one number to two different numbers.
Hope that made sense!