Since it is times 7 each time it will be 16807
She can make two triangle gardens with the six pieces of wood she has
8.66, you divide 12.99 into 3 and then multiply the result which is 4.33 by 2
The volume of a cylinder is given by the formula <em>V</em>=π<em>r</em>²<em>h</em>². In this instance, <em>r</em> is 4 and the height is 47-12 (the height of the cone at the bottom is 12 mm and the sand goes up to 47 mm on the top portion of the hourglass, including both the cone and cylinder) or 35 mm.
<em>V</em>=π(4²)(35)=560π mm³.
The volume of a cone is given by the formula <em>V</em>=1/3π<em>r</em>²<em>h</em>². In this instance, <em>r</em> is 4 and the height is 12 mm.
<em>V</em>=1/3π(4²)(12)=π(1/3)(12)(4²)=π(4)(4²)=64π mm³.
This gives a total volume of 560π+64π=624π mm³ of sand.
Since the sand goes down to the bottom at a rate of 10π mm³/second, it will take 624π/10π=62.4 seconds for the sand to all drain out.
