Section: Math Section 2

24)

Price of One Pack	Projected Number of Packs Sold
$0.75	10,000
$0.80	9,000
$0.85	8,000
$0.90	7,000
$0.95	6,000
$1.00	5,000

The chart above describes how many packs of gum a company expects to sell at a number of possible prices per pack. Which of the following equations best describes the relationship shown in the chart, where n indicates the number of packs sold and p represents the price in dollars of one pack?

1. n= -20,000p - 25,000
   
2. n= -20,000p + 25,000
   
3. n=-200p -250
   
4. n = 200p + 250
5. n = 20,000p - 25,000

Backsolving is a great way to answer this question. Pick a set of p and n from the chart; then, plug them in to each given equation to see whether the pair works.