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 add these radicals together their radicands must be the same:

8\( \sqrt{28} \) + 2\( \sqrt{7} \)
8\( \sqrt{4 \times 7} \) + 2\( \sqrt{7} \)
8\( \sqrt{2^2 \times 7} \) + 2\( \sqrt{7} \)
(8)(2)\( \sqrt{7} \) + 2\( \sqrt{7} \)
16\( \sqrt{7} \) + 2\( \sqrt{7} \)

Now that the radicands are identical, you can add them together:

Betty scored 87% on the test meaning she earned 87% of the possible points on the test. There were 140 possible points on the test so she earned 140 x 0.87 = 122 points. Each question is worth 2 points so she got \( \frac{122}{2} \) = 61 questions right.

The number of students taking German or Spanish is 13 + 9 = 22. Of that group of 22, 5 are taking both languages so they've been counted twice (once in the German group and once in the Spanish group). Subtracting them out leaves 22 - 5 = 17 who are taking at least one language. 27 - 17 = 10 students who are not taking either language.

If the tiger has consumed 99 pounds of food in 9 days that's \( \frac{99}{9} \) = 11 pounds of food per day. The tiger needs to consume 154 - 99 = 55 more pounds of food to reach 154 pounds total. At 11 pounds of food per day that's \( \frac{55}{11} \) = 5 more days.