Using simplex method, maximize Z(x, y) = 25x + 35y subject to \( 2x + 3y \le 15, \,\, 3x + y \le 12, \,\, x \ge 0, \,\, y \ge 0 \) Or a) A body…

   Using simplex method, maximize Z(x, y) = 25x + 35y subject to\( 2x + 3y \le 15, \,\, 3x + y \le 12, \,\, x \ge 0, \,\, y \ge 0 \) 

                                                                       Or

a) A body weight of 78 N is suspended by two strings of length 4m and 3m attached to two points in the same horizontal line whose distance apart is 5m. Find the tensions of the strings. 

b) A rocket is moving upward in the air. If it loses its mass at the rate of \( 0.2\text{ kgs}^{-1} \) and its velocity changes from \( 90\text{ ms}^{-1} \) to \( 10\text{ ms}^{-1} \), find the force retarding pressure the motion of the rocket.