Please help me I’m so confused?!?

There are 15 plates and each plate is either 7 or 12 inches diameter. which systems of equations do you use to find the number of 7 inch plates, x and 12 inch plates, y

Human body temperatures have a mean of 98.20° f and a standard deviation of 0.62°. sally's temperature can be described by z = 1.4. what is her temperature? round your answer to the nearest hundredth. 99.07°f 97.33°f 99.60°f 100.45°f

Julian wrote the following numeric pattern on the board3,10,17,24,31,38.what numbers of julian's pattern are compound numbers.