In order to find how many additional workers are needed to staff the extra crews you first need to calculate how many workers are on a crew. There are 12 workers at the company now and that's enough to staff 4 crews so there are \( \frac{12}{4} \) = 3 workers on a crew. 7 crews are needed for the busy season which, at 3 workers per crew, means that the roofing company will need 7 x 3 = 21 total workers to staff the crews during the busy season. The company already employs 12 workers so they need to add 21 - 12 = 9 new staff for the busy season.

A factorial has the form n! and is the product of the integer (n) and all the positive integers below it. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120.

The ratio of football cards to baseball cards is 7:2 and the ratio of baseball cards to basketball cards is 7:1. 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 49:14 and the ratio of baseball cards to basketball cards as 14:2. So, the ratio of football cards to basketball cards is football:baseball, baseball:basketball or 49:14, 14:2 which reduces to 49:2.

Calculate the number of vans needed by dividing the number of people that need transported by the capacity of one van:

vans = \( \frac{87}{8} \) = 10\(\frac{7}{8}\)

So, it will take 10 full vans and one partially full van to transport the entire team making a total of 11 vans.

By buying two shirts, Roger will save $11 x \( \frac{35}{100} \) = \( \frac{$11 x 35}{100} \) = \( \frac{$385}{100} \) = $3.85 on the second shirt.