15 handshakes each person shook hands exactly once. how many people are at the party?

Find the simple interest earned on $2600 invested for 3 years at 12% per annum

815 gallons of gas cost $32. How many gallons of gas can Mike buy for $20?

It has one more vertex than an octagon and 2 fewer sides than a hendecagon what is the shape

There are 24 children in a class, 16 brown-haired and 8 black-haired. Two students are randomly selected for a stage performance. Find the probability of the following selection. P (2 black haired children)

Solve the following equation. Then place the correct number in the box provided. x/6+4=20

What is the solution to 5=2/3x+1

If the length of the ramp will be 25 feet but the rise of the ramp will be 3.0 feet, approximately what will be the measure, in degrees, of the angle of elevation, angle A?

Is (-2) - 5 = 7? im not sure

light bulbs usually cost $2 they are on sale for 0.50 of the regular price. what is the sale price? is this a better price than if the sale price word 0.35 of the regular price?

Suppose that 10% of the general population has a disease and the test for the disease is accurate 80% of the time. What is the probability of testing postive for the disease