1) 12, 14
This is the answer because each increasing number was increased by 2, so if you add 2 to 10, you'd get 12. If you add 2 to 12, you would get 14.
2) 50, 54
Same explanation as above but for the number 4.
3) 68, 50
Same explanation as 1, but with subtracting the number 6.
4) 67, 69
Same as number 1
5) 103, 101
Same as number 3 but subtracting the number 2
Hope this helps!!! :)