Question Bank / Math / Area and Volume
Area and volume SAT question
Math · Geometry and Trigonometry · Hard · Answer it here, explanation included.
Two identical rectangular prisms each have a height of . The base of each prism is a square, and the surface area of each prism is . If the prisms are glued together along a square base, the resulting prism has a surface area of . What is the side length, in , of each square base?
ExplanationShow
Choice B is correct. Let represent the side length, in , of each square base. If the two prisms are glued together along a square base, the resulting prism has a surface area equal to twice the surface area of one of the prisms, minus the area of the two square bases that are being glued together, which yields . It’s given that this resulting surface area is equal to , so . Subtracting from both sides of this equation yields . This equation can be rewritten by multiplying on the left-hand side by , which yields , or . Adding to both sides of this equation yields . Multiplying both sides of this equation by yields . The surface area , in , of each rectangular prism is equivalent to the sum of the areas of the two square bases and the areas of the four lateral faces. Since the height of each rectangular prism is and the side length of each square base is , it follows that the area of each square base is and the area of each lateral face is . Therefore, the surface area of each rectangular prism can be represented by the expression , or . Substituting this expression for in the equation yields . Subtracting and from both sides of this equation yields . Factoring from the right-hand side of this equation yields . Applying the zero product property, it follows that and . Adding to both sides of the equation yields . Dividing both sides of this equation by yields . Since a side length of a rectangular prism can’t be , the length of each square base is .
Choice A is incorrect and may result from conceptual or calculation errors.
Choice C is incorrect and may result from conceptual or calculation errors.
Choice D is incorrect and may result from conceptual or calculation errors.
Drill this skill on Aceit
Adaptive practice, a daily plan, and score tracking take a free account so we can save your work.
More Area and volume questions
- A right circular cylinder has a volume of . If the height of the cylinder is 5, what is the radius of the cylinder?
- Square A has side lengths that are 166 times the side lengths of square B. The area of square A is k times the area of square B. What is the value of k ?
- The side length of a square is 55 centimeters cm. What is the area, in cm2, of the square?
- What is the length of one side of a square that has the same area as a circle with radius 2 ?
- Square X has a side length of 12 centimeters. The perimeter of square Y is 2 times the perimeter of square X. What is the length, in centimeters, of one side of square Y?
- The area of a square is 64 square inches. What is the side length, in inches, of this square?