"ARITHMETIC PROGRESSION. A sequence of numbers in which any number, or term, after the first can be obtained by adding a fixed number COMMDIFF to its predecessor. Example 12, 22, 32, 42... or 27, 25, 23, 21... Ans(a) Set INDEX#A=1, INDEX#b=2, TERM#A=30, TERM#B=55, N=12. Value of 12th term is 305. Sum of first 12 terms is 2010. Ans(b) Set INDEX#A=1, INDEX#B=2, TERM#A=108, TERM#B=100, N=15. Sum of first 15 terms is 780. Type any key to exit. (c) Copyright PCSCC, Inc., 1993 ||(a) Find the 12th term and the sum of the first 12 terms of thearithmetic progression 30, 55, 80, 105 ... (b) Find the sum of the first 15 terms of the arithmetic progression 108, 100, 92, 84... Type comma key to see answers. Type (F2) to return to helpfile."