A sphere with diameter (2m + 5)cm in placed inside a cylinder such that it exactly fits in the cylinder. (See the figure). If the height of the cylinder is 21 cm, then find the value of m and the curved surface area of the sphere
18. The sum of the numerator and the denominator of fraction is 4 more than twice the numerator. If 3 is added to each of the numerator and denominator their ratio becomes 2:3. Find the