Q. 1. If a1, a2, a3, a4 are the n terms of an A.P. Derive the formula for its nth term. Q. 2. If a1, a2, a3, a4 ... are the n terms of an A.P. Derive the formula for the sum of its n terms. Q. 3. If nth term of an A.P. is given by an = 5n-3. Find the sum of its 50 terms. Q. 4. Sum of n terms of a sequence is given by S = 2n - 2n. If it is an A.P. then find its 20th term. Q. 5. Find the sum of the following series: 10+14 +18+22+ ....104