If p is a prime number, for how many values of p is p^2 + 21p - 1 also prime?

The average (arithmetic mean) of 7 numbers in a certain list is 12. The average of the 4 smallest numbers in this list is 8, while the average of the 4 greatest numbers in this list is 17.

A panel of 6 judges is being selected from a group of 10 males and 10 females. What is the probability of selecting exactly 3 male?

Maple grove wants to include two types of maple trees, the namesake of the city for their parks. Two varieties of maple trees have been selected one cost $75 per tree the other cost $90 per tree the budget must not exceed 70,000 people want more of

The area of a rectangular sign is 51ft square. The base of the sign is 16 ft. What is the height of the sign?

The smallest of three consecutive integers is 1515 less than the sum of the two larger integers. find the three integers.

There is a geometric theorem that says if two lines are perpendicular to the same line, they are parallel to each other explain why this is true by writing & comparing equations

How do you graph (y=-1/2x-1) (y=-3x+4)

A motorboat travels 448 kilometers in 8 hours going upstream and 516 kilometers in 6 hours going downstream. What is the rate of the boat in still water and what is the rate of the current?

Jack made 50% more smoothies than yesterday. If he made 30 smoothie today how many did he make yesterday?

Mr. Ramirez has enough money to fence one of his rose gardens, how many feet of fencing will he need if both gardens have the same perimeter