Answer:
8 people in the original group.
Step-by-step explanation:
Let x be the number of people who were originally present for the dinner that cost $160. Their average cost per person would be:
$160/x
If 2 more people join, there are x+2 people. Ignoring the awkward situation that they apparently did not order any additional food, they agree to share the cost of the dinner. The average cost is now:
$160/(x+2)
We are told that this new average is now $4 less per person.
$160/(x+2) = ($160/x) - $4
$160 = (($160/x) - $4)(x+2)
x = 8 people
Answer:

General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
<u>Geometry</u>
- Volume of a Rectangular Prism: V = lwh
<u>Calculus</u>
Derivatives
Derivative Notation
Differentiating with respect to time
Basic Power Rule:
- f(x) = cxⁿ
- f’(x) = c·nxⁿ⁻¹
Step-by-step explanation:
<u>Step 1: Define</u>
<u />
<u />
<u />
<u>Step 2: Differentiate</u>
- Rewrite [VRP]:

- Differentiate [Basic Power Rule]:

<u>Step 3: Solve for Rate</u>
- Substitute:

- Multiply:

Here this tells us that our volume is decreasing (ice melting) at a rate of 360 cm³ per hour.
80% of quizzes + 20% of final = final grade
80% * 73 + 20% * x = 70
0.8 * 73 + 0.2x = 70
58.4 + 0.2x = 70
0.2x = 11.6
x = 58
Length times width times height.