The distance between the centres of two circles is 61 cm and their radii are 35 cm and 24 cm. What is the length (in cm) of the direct common tangent to the circles?
If compound interest received on a certain amount in the 3rd year is Rs. 1,240, what will be the compound interest (in Rs) for the 4th year on the same amount at 9% rate of interest?
A right circular solid cylinder has radius of base 7 cm and height is 28 cm. It is melted to form a cuboid such that the ratio of its side is 2 : 3 : 6. What is the total surface area (in cm2) cuboid?