If a and b are the lengths of two sides of a triangle such that the product ab = 24, where a and are integers, then how many such triangles are possible?

The sum of the radius of the base and the height of a closed solid cylinder is 12.5 cm. If the total surface area of the cylinder is 275 sq.cm, then its radius is

Let O be the centre of a circle. PA and PB are tangents to the circle from a point P outside the circle and A and B are points on the circle, If angle APB = 50 deg, then angle OAB is equal to:

Two circles of radii 20 cm and 5 cm, respectively, touch each other externally at the point P, AB is the direct common tangent of those two circles of centres R and S, respectively. The length of AB is equal to: