Help pls

Learning Task 2 :
Find the missing term in the following equal pair of ratios.
1. 8 : 18 = 4 : N 6. 12 : N = 30 : 60
2. 4 : 16 = 1 : N 7. 19 :18 = 95 : N
3. 3 : N = 12 : 4 8. 30 : N = 15 : 50
4. N : 9 = 10 : 45 9. 40 : 50 = 20 : N
5. 27 : 3 = N : 1 10. 25 : 10 = N : 30