If 10% of a number is 2 less than 20% of the same number, then 80% of the number equals?

Ablock of wood is a cube whose side is x in. long. you cut off a 1-inch thick piece from the entire right side. then you cut off a 3-inch thick piece from the entire top of the remaining shape. the volume of the remaining block is 2,002 in3. what are the dimensions of the original block of wood?

How do i do this activity, is appreciated

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10