For c, it would be 111 because 10^2 = 100 and 10^1 is 10 and so on.
For 2a, it would be 100. Basically the exponent is how many zeros is after the one.
For 2b, 1000000000 or 10^9
For 2c, 100000000 or 10^8
2d, 100000 or 10^5
2e, 100000000 or 10^8
Hope this helps!
I have checked this with my best effort, so try to fix some mistakes you might find by yourself! (There probably aren't any)
