1.the 19th term of a.p is equal to 3 times its 6th term if the 9th term of the a.p is 19. Find the first term and it's common difference.
2. If 8 times the 8th term of an a.p is equal to the 12 times the 12th term of a.p then find the 20th term .
3. Explain the reason for the double answer .
4.find a30-a20 for the A. P .5,1,-3,-7........
5.find the number of terms of the a.p 20,16,12,....which when added gives the sum 56. Request for answer as soon as possible....plz ...friends.