What is the missing number pls help

So in order to find the missing number, we must find the difference with the numbers that we were given.

Problem #1

42-30= 12 and 84-69= 15. It's possible that each difference increases by one Let's see...

30+12= 42

42+13= 55

55+14 = 69

69+15 = 84

So for 1., all you have to do is keep adding the difference and increase it by 1 each time. If you wanted to keep increasing, you would add 84+16, then 100+17, etc.

Problem #2: As for the second one, I had trouble solving it, sorry :(.

Problem #3

3. For the third problem, 27-22= 5 and 9-1=8. It looks like each difference increased by 1.

27-22 = 5

22-6 = 16

16-7 = 9

9-8= 1