What is the probability that at least 2 people have the same birthday in a group of 9 people? Assume that there are 365 days in a year.

Solve each quadratic equation by factoring and using the zero product property. x^2 - 8x + 30 = 3x

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.

In a singing competition, there are 150 participants. at the end of each round, 40% of the participants are eliminated. how many participants are left after n rounds?