1. If 1/(b + c), 1/(c + a), 1/(a + b) are in AP then

2. If the sum of the first 2n terms of the A.P. 2, 5, 8, ….., is equal to the sum of the first n terms of the A.P. 57, 59, 61, ….., then n equals

3. The sum of AP 2, 5, 8, …..up to 50 terms is

4. If a is the A.M. of b and c and G₁ and G₂ are two GM between them then the sum of their cubes is

5.  pth term of an A.P. is q and qth term is p, its (p+ q)th term is

6. The sum of two numbers is 13/6 An even number of arithmetic means are being inserted between them and their sum exceeds their number by 1. Then the number of means inserted is

7. If the third term of an A.P. is 7 and its 7 th term is 2 more than three times of its third term, then the sum of its first 20 terms is

8. The sum of n terms of the series (1/1.2) + (1/2.3) + (1/3.4) + …… is

9. If 2/3, k, 5/8 are in AP then the value of k is

10. The first term of a GP is 1. The sum of the third term and fifth term is 90. The common ratio of GP is

11. If the roots of the cubic equation ax³ + bx² + cx + d = 0 are in G.P., then

12. The 35th partial sum of the arithmetic sequence with terms a_n = n/2 + 1

13. Let Tr be the r th term of an A.P., for r = 1, 2, 3, … If for some positive integers m, n, we have Tm = 1/n and Tn = 1/m, then Tm n equals

14. For a G.P. the ratio of the 7th and the third terms is 16. The sum of 9 terms is 2555. What is the first term?

15. If the sum of the roots of the quadratic equation ax² + bx + c = 0 is equal to the sum of the squares of their reciprocals, then a/c, b/a, c/b are in