What is the square root of -16

Mustafa contributes 11% of his $67,200 annual salary to his 401k plan. what is his pretax income

3women sell hats at a craft fair weekly. the money they make at the fair is split into categories. 9% goes to pay taxes. $55 goes to pay rent for the space they sell in. the rest is split between the women. if the group make $706 at the fair, how much does each women get paid once the money is divided

Ken earned $128 from his part-time job this summer. he spent 25% of his money on games. he is going to donate 1/6 of the remaining money to charity. how much money will the charity receive?