Answer:
10.) If you buy all larger cans (aka the 7-gallon cans), you would have saved approx. $30.21
9.) Seth would need a score of 95% in order to average an 80%
Step-by-step explanation:
10.) It costs $15.50 per 5-gal. If you want to buy 45 gallons, it would cost you <u>$139.50</u> if you bought 5-gallon cans.
It costs $17.00 per 7-gallon. If you want to buy 45 gallons, it would cost you <u>$109.29</u> if you bought 7-gallon cans.
Now, let's compare prices. Buying 45 gallons worth of 7-gallon cans is less expensive by.... (139.50 - 109.29 = 30.21)
Therefore, you saved $30.21.
9.) An average is done by adding up all the numbers and dividing it by how many numbers you added it by. Let's write an equation to make things easier. So far, we don't know the score he needs to get on his fourth test so let's make it a variable x.
(82 + 68 + 75 + x) / 4 = 80
Let's solve for x.
(82 + 68 + 75 + x) / 4 = 80 *Multiply both sides by 4
82 + 68 + 75 + x = 320 *Add like terms
225 + x = 320 *Subtract 225 from boths to get x on one side
x = 95
