Mr. Greene bought some pens at a school supply store, including 15 blue pens.
60% of all the pens he bought were blue.
How many pens did Mr. Greene buy in all?

Determine the mean and variance of the random variable with the following probability mass function. f(x)=( 729divided by 91) (1 divided by 9) superscript x baseline comma x equals 1,2,3 round your answers to three decimal places (e.g. 98.765).

Noor brought 21 sheets of stickers. she gave 1/3 of a sheet to each of the 45 students at recess. she wants to give teachers 1 1/2 sheets each.

Drag each equation to the correct location on the table. for each equation, determine the number of solutions and place on the appropriate field in the table.