Please help with 2 and 3

Abicycle training wheel has a radius of 3 inches. the bicycle wheel has a radius of 10 inches.approximately how much smaller, in square inches and rounded to the nearest hundredth, is the area of the training wheel than the area of the regular wheel? *

Acollege student takes out a $7500 loan from a bank. what will the balance of the loan be after one year(assuming the student has not made any payments yet) a. if bank charges 3.8% interest each year ?

The base of pyramid a is a rectangle with a length of 10 meters and a width of 20 meters. the base of pyramid b is a square with 10-meter sides. the heights of the pyramids are the same. the volume of pyramid a is the volume of pyramid b. if the height of pyramid b increases to twice that of pyramid a, the new volume of pyramid b is the volume of pyramid a.