Please help?

a) The common difference is 1. The Nth term is a+(n-1)d, where "a" is the first term and "d" is the common difference. Subtracting the first term from the last gives (n-1)*d, which is 300 for this sequence. If d=1, then n=301. There are 301 terms in the sequence.

b) The Nth term has power (n-1). There are 51 terms.

c) The common difference is 100. Using the same method as for (a), we have (n-1)*100 = 20000 - 100 = 19900. n = (19900/100)+1 = 200. There are 200 terms. (If you drop 2 zeros, you see the terms are numbered 1, 2, ... 200.)

d) The Nth term has power (n-1). The last term is 2^9, so there are 10 terms.