The mean of marks secured by 50 students in division A of class X is 61, 25 students of division B is 57 and that of 50 students of division C is 55. What will be the mean of marks of the students of three divisions of Class X?
A manufacturer faces a -1.2 price elasticity of demand for its product. It is presently selling 7,500 units/day. If it wants to increase quantity sold by 9%, it must lower its price by