There are 72 boys. 7:6 = 84:?, divide 84 by 7, you get 12. Multiply 6 by 12 to get the answer.
Easy and fast way to do it:
Go to google and type, " volume of a cone calculator" and type in the radius and height.
Answer: The answer is 12.5 ft.
Step-by-step explanation: Given that there is a rectangle with ratio of its length to breadth 8 : 5. Also, the longer side of the rectangle is 20 feet. We are to find the length of the shorter side.
Let, '8x' and '5x' be the length and breadth of the rectangle respectively. Since length is the longer side, so we have

Therefore, width, length of the shorter side will be

Thus, the length of the shorter side is 12.5 ft.
Area of rectangle is length x width
area of smaller rectangle
9x5=45
area of large rectangle
11x7=77
77-45=32
2:1 is the ratio
- Rach :)