There are 10 doors to a coliseum. In how many ways can a person go in and out if one can enter any door but leave using another door? Use permutation formula (P(n, r)) to solve.

The average hourly earnings for a construction worker is projected to be $24.50 in 2012. jason wants to join the construction work force after he graduates in 2012. his friend tells him that average hourly earnings for construction workers will rise by 2% from 2009 to 2012. based on the data below, assuming that the projected hourly earnings are correct, is jason’s friend’s statement accurate? construction industry - average hourly earnings, 2000-2009 a. his friend’s statement is accurate. the average hourly earnings will increase by 2%. b. his friend’s statement is not accurate. the percent increase will be more than 2% c. his friend’s statement is not accurate. the percent increase will be less than 2% d. his friend’s statement is not accurate. the average hourly earnings will decrease

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10