CBSE Class 11science Maths Sequences and Series

please answer
 1. Sum of 10 A.M's between 3,10 is..? 2.if (4x+4)/3, 2x+2,3x+3 are in G.P then 4th Term is.. 3.which term of 21/root2 +1/4 so on .. is 1/32. 4.sum to n terms of 3.5+4.7+5.9+ so on..

9th sum
 Define arithmetic mean for an A.P. a, b, c.
 If A_{1}, A_{2}, A_{3}, …, A_{n} are n arithmetic means between a and b. Find the common difference between the terms.
 Find the arithmetic mean between .
 Find the number of arithmetic means between 7 and 71 in such a way that 5^{th} mean is 27.
 Insert 6 numbers between – 6 and 29 such that the resulting sequence is an A.P.
 Between 1 and 31, n numbers have been inserted in such a way that the resulting sequence is an A. P. and the ratio of 7th and (n – 1)^{th} numbers is 5 : 9. Find the value of n.
 If x, y, z are in A.P. A_{1} is the mean of x & y and A_{2} is the mean of y & z. Then prove that the mean of A_{1} and A_{2} is y.