As previously discussed, it suggests that using CFLs is a good idea from a purely financial perspective unless you live in an area where power is relatively inexpensive, but there is another wrinkle. Suppose you have a residence with a lot of incandescent bulbs that are used on average 500 hours a year. The average bulb will be about halfway through its life, so it will have 500 hours remaining (and you can’t tell which bulbs are older or newer). At what cost per kilowatt-hour does it make sense to replace your incandescent bulbs today?

Solve each percent problem. What is 20% of 3?

Find the time requested, to the nearest 0.1 year. The time it would take $6,000 to grow to$10,000 at 4.75% interest compounded monthly

Determine whether the statement is true or false. Use the following sets of numbers.

$N=$ set of natural numbers.

$Z=$ set of integers

$I=$ set of irrational numbers

$Q=$ set of rational numbers

$\mathbb{R}=$ set of real number

$$Z \subseteq \mathbb{P}$$

Find the Errors. Locate as many as you can.

#include <iostream>
using namespace std;
struct ThreeVals
{
    int a, b, c;
};
int main()
{
    ThreeVals vals = {1, 2, 3};
    cout << vals << endl;
    return 0;
}

Write each set in roster form and in set-builder notation. P is the set of natural numbers that are factors of 25.

The distance from the surface of a lens to the focal point is the

Find the rotation–dilation matrix within the given matrix.

$$\left[\begin{array}{rr} 1 & -2 \\ 1 & 3 \end{array}\right]$$

Riley and Rhoda plan to buy several bags of dog food and a dog collar. Each bags of dog food costs $7, and the dog collar costs$5. a. Use the information above to write an expression for the amount of money they will spend if they buy b bags of food. b. Riley and Rhoda have $30. Use this information and the expression you wrote for Part (a) to write an inequality for finding the number of bags of food they could buy. c. Solve the inequality and graph the solutions. Check your answer in the original situation.

Use a rotation matrix to rotate the vector

$$\left[\begin{array}{l} -2 \\ -3 \end{array}\right]$$

counterclockwise by the angle $\pi / 9.$

Why is the flow of smoke from a cigarette frequently laminar near the source but turbulent further away? Explain.

Find the time requested, to the nearest 0.1 year. The time it would take $6,000 to grow to$10,000 at 4.75% simple annual interest

Find the distance between the two points. If necessary, you may draw graphs but you shouldn't need to use the distance formula.

$(0,0)$ and $(3,4)$

Solve the problem.

The polar equation

$$r=\frac{a\left(1-e^2\right)}{1+e \cos \theta}$$

can be used to graph the orbits of the planets, where $a$ is the average distance in astronomical units from the sun and $e$ is a constant called the eccentricity. The sun will be located at the pole.

Plot the orbits of Earth, Jupiter, Uranus, and Pluto on the same polar grid. How does Earth's distance from the sun compare to the other planets' distances from the sun?