Helpp plz and explain answer

What is the volume of this square pyramid?

You are making a blueprint of your bedroom and you plan to use a scale factor of 18 . the actual width of your room is 14 feet and the actual length of your room is 16 feet. determine the width and length of your room on the blueprint. on the blueprint, your room will have a width of feet and a length of feet.

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