There are 20 students in class and each student was asked to give a chart for 10 different counties in the state of Texas. What is the probability that at least 25% of the counties had a chart turned in?

Aiden buys two bags of chips at $1.09 each and a 20 ounce soda for $1.20 at the gas station. he knows that the state tax is 5.5. how much change will he receive from a $5 bill?

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Suppose that the price p, in dollars, and the number of sales, x, of a certain item follow the equation 4 p plus 4 x plus 2 pxequals56. suppose also that p and x are both functions of time, measured in days. find the rate at which x is changing when xequals2, pequals6, and startfraction dp over dt endfraction equals1.5.