26. The 6th term of the expansion x6 - 3 15309 A. 15309 8x5 C. - 15309 D 15309 8x4 8x5 8x4 27. For all positive integral values of 5 - 1 is divisible by A. 2 B. 4 C . 5 D. both a and b 28. For every positive integer n, 2 + 4 + 6 + ... + 2n = A. n2+ 1 B. n + 1 C. n (n + 1) D. n (n - 1) 29 . ( a + x ) " = [ = ( " ) an - x " A. Is called a binomial theorem B. Is called a mathematical induction C. Is called an extended mathematical induction D. None of these 30. The inequality 3n 2 B. n > 3 C. n > 4 D. n > 6