When tow solids of similar shape that is assuming to be a box in this case, having a length ratio of 2:9, we get the ratio of the surface areas equal to the<span>square of the ratio of their edges. This is becaue the surface area is equal to the area of the base (square) which is the square of the side. Answer is B.</span>
They are both correct in their computation
(28.5-28.5(.3))+.1(28.5-28.5(.3))=$21.945
28.5(.7)(1.1)=$21.945
And since they each have $22 to spend, they have enough to purchase the book.
Start with how much profit they are making off each race entry. People pay $55 to race, but $15 of that is expenses so they are only profiting $40 for each entry. Now write one side of the equality. They start with $10,000 in donations, and then have a $40 profit for each race entry. So 10,000+40x. X will represent the unknown number of race entries. What do we want that expression to be equal to? We want 10000+40x>55000. It can also be greater than or equal to, not just greater than.
Solve for x. Subtract 10000 from each side resulting in 40x>45000. Divide each side by 40 to solve for x. X>1125. X needs to bbe greater than or equal to 1125. If there are 1125 race entries, the charity will profit exactly $55000, so the lowest number of race entries is 1125
B = hourly rate for babysitting and w = hourly rate for working at water park
3b + 10w = 109...multiply by -8
8b + 12w = 177...multiply by 3
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-24b - 80w = - 872 (result of multiplying by -8)
24b + 36w = 531 (result of multiplying by 3)
---------------------add
- 44w = - 341
w = -341/-44
w = 7.75 <=== hourly rate for working at water park
3b + 10w = 109
3b + 10(7.75) = 109
3b + 77.50 = 109
3b = 109 - 77.50
3b = 31.50
b = 31.50/3
b = 10.50 <== hourly rate for babysitting