The mean of marks secured by 55 students in division A of class X is 58, 45 students of division B is 54 and that of 75 students of division C is 52. Find the mean of marks of the students of three divisions of Class X.

Find k, if the line 4x - y = 1 is perpendicular to the line 5x - ky = 2?

Simple interest on a certain sum of money for 3 years at 18% per annum is half the compound interest on Rs. 9000 for 2 years at 10% per annum. The sum placed on simple interest is:

A vendor buys pens at the rate of 4 for Rs 5 and sells at the rate of 4 for Rs 3. What will be the result?

What is the length of the side of an equilateral triangle, if its area is 64√3 sq cm?

A cone of radius 7 cm and height 12 cm is completely filled with water. This water is emptied into an empty cylindrical vessel of radius 3.5 cm. What will be the height of water in this vessel?

If 1 + secA = x, then the value of x is

If √[(1 - cosA)/2] = x, then the value of x is