A solid cone of height 36 cm and radius of base 9 cm is melted to form a solid cylinder of radius 9 cm and height 9 cm. What percent of material is wasted this process?
Rs. x invested at 8% simple interest per annum for 5 years yields the same interest as that on Rs. y invested at 7.5% simple interest per annum for 6years. Find x : y.
Product of digits of a 2-digit number is 24. If we add 45 to the number, the new number obtained is a number formed by interchange of the digits.What is the original number?