The ratio of red to yellow balloons is 3: 2 respectively. if there are 18 red balloons, how many yellow balloons are there?

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

:24% of students in a class are girls. if there are less than 30 students in this class, how many students are there? how many girls are there?

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500