Equations Part-3

11) Find the positive value of k for which      the equations : x² + kx  + 64 = 0 and        x^{2  _} 8x  + k = 0 will have real roots:       (a) 12       (b) 16       (c) 18       (d) 22

12) If one root of the equation x^2_3x+k =0        is 2, then value of k will be         (a) -10        (b) 0        (c) 2        (d) 10

13) A man starts his job with a certain        monthly salary and earns a fixed increment       every year. If his salary was Rs. 1500 after 10        years of service, what was his starting salary         and what is the annual increment in rupees?        (a) Rs. 1300 , Rs. 50        (b) Rs. 1100 , Rs. 50        (c) Rs. 1500 , Rs. 30        (d) None

14) The value of k for which the points (k, 1),         (5 , 5) and( 10, 7) may be collinear is:

        (a) k = -5

        (b) k = 7

        (c) k = 9

        (d) k = 1

15) Roots of the equation 3x² - 14x  + k = 0         will be reciprocal of each other if:       (a) k = -3       (b) k = 0       (c) k = 3       (d) k = 14