The ten's digit of a 2digit number is greater than the units digit by 4. If we subtract 36 from the number, the new number obtained is a number formed by interchange of the digits. Find the number.
The diagonal of a square equals the side of an equilateral triangle. If the area of the square is 12 sq cm, what is the area of the equilateral triangle?
By increasing the price of entry ticket to a fair in the ratio 13:16, the number of visitors to the fair has decreased in the ratio 11:9. In what ratio has the total collection increased or decreased?