Answer:
The "chemist" would need to purchase 20,000 matchbooks, and the associated expense would be $28,800.
Explanation:
To determine how many matchbooks the "chemist" needs to purchase, we first need to calculate how much red phosphorous is required for 4 separate "cooks".
25 grams of red phosphorous is required for one cook, so for 4 cooks, the total amount needed would be:
25 grams/cook * 4 cooks = 100 grams
Next, we'll calculate how many matchbooks are needed to obtain 100 grams of red phosphorous. Each matchbook contains 0.005 grams of red phosphorous, so the number of matchbooks required is:
100 grams / 0.005 grams/matchbook = 20,000 matchbooks
Finally, to find the associated expense, we'll multiply the number of matchbooks by the price per matchbook:
20,000 matchbooks * $1.44/matchbook = $28,800
Therefore, the "chemist" must purchase 20,000 matchbooks, and the associated expense would be $28,800.