BB pg 613-614 10-12

<p>I need help with these questions for number 10 i got the answer right its 12..but<br>
i didnt it in a weird way since there were just 4 red and 6 blues..I added them two and added the ones and got 12 is this the right way...11 i get some what and 12 i just dont get it all..thnx for all the help.</p>

<p>Anyone?????</p>

<p>hi--</p>

<p>for 11, you're being asked what the result is when you divide the total of a set of numbers by the average of the numbers. so let's say the individual numbers are x, y, and z, and their average is a:</p>

<p>(x + y + z)/3 = a</p>

<p>so what would we get if we divided (x + y + z) by a?</p>

<p>(x + y + z)/3 = a
(x + y + z) = 3a
(x + y + z)/a = 3</p>

<p>so k in the problem is the number of prices on the list.</p>

<p>an easier/faster way to do this is just to think about what an average is--it's the ratio of the total to the number of items that make up the total. so if we divide the total by the average, the result has to be the number of items in the total.</p>

<p>for 12, you're being asked to find the lengths of the solid line segments. the solid line segments are the equal legs of isosceles triangles, and the bases of those triangles are also the sides of a square with area 81.</p>

<p>if the square's area is 81, then each side is 9. the means the base of each isosceles triangle is 9. if the perimeter of each triangle is 30 and the base is 9, then the other two sides of the triangle are each ((30 - 9)/2 = ) 10.5. since there are 8 of these sides making up the solid line, then the answer is 8 * 10.5 = 84.</p>

<p>sorry that both of those explanations are kind of meh. i'm a little off my game today :)</p>

<p>10: The answer MUST be a multiple of 4 and 6 since you can't have half a marble. The answer is thus B.</p>