Alan initially has 17 friends. He loses some and then has 13 friends. Find the percent change in friends that he has.

The final price of a computer is $365. This is after a 19% tax and 22% discount. Find the initial price.

Samantha’s initial grade is 88. Her final grade is 95. Find the percent change in her grade.

The initial price of a water bottle is $1.55. Find the price after a 7% tax and 18% discount.

Solve for the following values: sin30 cos 30 sin 45 cos 330 cos 300 sin 225 cos 210 sin 240 cos 135 sin 150 cos 180 sin 270

Find the area of an equilateral triangle with side length of 10.

A circle graph has 5 categories, each representing the favorite colors of a group of students. 16 prefer purple, 12 prefer blue, 9 prefer green, 18 prefer pink, and 10 prefer orange. Find the central angle for the color blue.

Find the equation of a circle with endpoints (5,8) and (-4,9).

Andrew drove 100 miles at an average speed of 50 mph. He then increased his speed by 20% and drove another 30 miles. What was the average speed for the entire journey?

In a physics problem, rate is inversely related to time for a given distance. When time is 4 hours, rate is 42 miles per hour. Find the rate when time is 6. Now, find the time when rate is 54 mph.