Answer
\$13.50 per day
Work Step by Step
Looking at the table and using mental math, we see that the number of calories needed per day for each horse is 15,000. If h is the number of horses, the number of calories needed per day is $15000h$ calories.
Find the number of calories needed per day for 6 horses by substituting 6 for h.
Let d be the daily calories needed.
$d=15,000(6)=90,000$ calories
The daily cost is $0.15(d\div1000)$. The daily calories are divided by 1000 because the cost is given per 1000 calories.
Substitute 90,000 calories for d to find the daily cost to feed 6 horses. Let t be the total daily cost.
$t=0.15\times90000\div1000=0.15\times90=13.50$
