Find the value of $$ {5^{1\over2}-[3^{1\over4}+6-4÷2]}$$

The area of the base of a right circular cone is 400π and its height is 15 cm. The curved surface of the cone ( in cm²) is:

The curved surface area of a cylindrical pillar is $$ {264 m^{2}}$$ and its volume is $$ {924 m^{3}}$$. Find the ratio of its diameter to its height.

₹12,000 is lent for one year t the rate of 15% per annum, the interest being compounded annually. If the compounding of the interest is done half- yearly, then how much more interest will be obtained at the end of the one-year period on the same initial sum?

The salary of P, Q and R are in the ratio of 3 : 4 : 5. The salary of P, Q and R together is Rs. 33600 by what per cent is the salary of R more than that of P ?

Salim's age is 10 years. His grandfather's age is 62 years. After how many years will his grandfather's age be five times that of Salim?

The volume of a solid right circular cone is 600 π cm³, and the diameter of its base is 30 cm. The total surface area (in cm²) of the cone is:

In a school, if there are 36% boys and 352 girls, then the number of boys is ________.