1. Find the sum of the first five terms of the series 20 +27 +34 + ... 2. Find the sum of the first 7 terms of an arithmetic series whose first and last terms are 6 and 36, respectively. 3. A finite arithmetic sequence has 10 terms. If the first and last terms of the sequence are 12 and 38 respectively, find S10- 7 4 3 4. Find the sum of the arithmetic series-+-+-+...+11. 6 3 2
