16. Smallest positive x satisfying the equation cos 3x + cos5x = 8cos 4x cosx is (a) 15 (b) 18 (c) 22.5 17. The set of values of x satisfying simultaneously the inequalities (d) 30 (x-8)(2-x) 10 logo3 (log, 5-1) 7 5-1)) and 23-31>0 is: (a) a singleton set (c) an infinite set (b) an empty set (d) a set consisting of exactly two elements 18. A bag contains 2 white and 4 black balls. A ball is drawn 5 times, each being replaced before another is drawn. The probability that atleast 4 of the balls drawn are white is: 4 (a) 81 (b) 10 243 11 (c) 243 (d) None 19. The modulus of the complex number z such that |z+3-i = 1 and arg(z) = is equal to (a) 1 (b) 2 (c) 3 (d) 4 e-1 1 x+2x-1 20. Let J = -exp. dx and K=xen x exp. x+1 2 Exinx ext x-2 dx. The value of (J + K) is equal to 2 0 e+1 (a) (e) (b) (e) e2-1 (c) 0 (d) (e) -2