John left a 20% tip on a $40.00 dinner bill how much was the tip

How many real and imaginary solutions does the equation x^2-3x=-2x-7 have?

Bobby bought 1.12 pounds of turkey at a cost of 2.50 per pound. carla bought 1.4 pounds of turkey at a cost of 2.20 per pound. who spent more and by much?

What is the interquartile range of this data set? 2, 5, 9, 11, 18, 30, 42, 48, 55, 73, 81