The ratio of football cards to baseball cards is 5:2 and the ratio of baseball cards to basketball cards is 5:1. To solve this problem, we need the baseball card side of each ratio to be equal so we need to rewrite the ratios in terms of a common number of baseball cards. (Think of this like finding the common denominator when adding fractions.) The ratio of football to baseball cards can also be written as 25:10 and the ratio of baseball cards to basketball cards as 10:2. So, the ratio of football cards to basketball cards is football:baseball, baseball:basketball or 25:10, 10:2 which reduces to 25:2.

To find the average of these 4 numbers add them together then divide by 4:

\( \frac{9 + 5 + 9 + 5}{4} \) = \( \frac{28}{4} \) = 7

The commutative property states that, when adding or multiplying numbers, the order in which they're added or multiplied does not matter. For example, 3 + 4 and 4 + 3 give the same result, as do 3 x 4 and 4 x 3.

If a single cook can bake 2 large cakes per hour and the kitchen is available for 3 hours, a single cook can bake 2 x 3 = 6 large cakes during that time. 37 large cakes are needed for the party so \( \frac{37}{6} \) = 6\(\frac{1}{6}\) cooks are needed to bake the required number of large cakes.

If a single cook can bake 19 small cakes per hour and the kitchen is available for 3 hours, a single cook can bake 19 x 3 = 57 small cakes during that time. 230 small cakes are needed for the party so \( \frac{230}{57} \) = 4\(\frac{2}{57}\) cooks are needed to bake the required number of small cakes.

Because you can't employ a fractional cook, round the number of cooks needed for each type of cake up to the next whole number resulting in 7 + 5 = 12 cooks.

Christine scored 84% on the test meaning she earned 84% of the possible points on the test. There were 200 possible points on the test so she earned 200 x 0.84 = 168 points. Each question is worth 2 points so she got \( \frac{168}{2} \) = 84 questions right.