Question: Bill gets a flat-screen TV that measures 48 inches by 100 inches. His brother Bob gets a TV that measures 70 inches by 60 inches. If the TVs weigh 4 oz per square inch of screen space, how much more does the heavier TV weigh in pounds? (There are 16 ounces per pound).
Answer with step-by-step thinking: First find the screen area of Bill's TV: 48 inches * 100 inches = 4800 square inches. Then find the screen area of Bob's TV: 70 inches * 60 inches = 4200 square inches. Then subtract the size of the smaller TV from the size of the bigger TV to find the size difference: 4800 square inches - 4200 square inches = 600 square inches. Then multiply the size difference by the weight per square inch to find the weight difference: 600 square inches * 4 oz / square inch = 2400 oz. Then divide the weight difference in ounces by the number of ounces per pound to find the weight difference in pounds: 2400 oz / 16 oz / pound = 150 pounds.
So the answer is 150.

Question: There are 40 students in the 6th grade. 25% of them wear glasses and 40% of them wear contact lenses. How many students do not wear any vision assistance wear?
Answer with step-by-step thinking: There are 40 x 25% = 10 students who wear glasses. There are 40 x 40% = 16 students who wear contact lenses. There are 10 + 16 = 26 students who wear vision assistance. There are 40 - 26 = 14 students who do not wear any vision assistance wear.
So the answer is 14.

Question: Two brick walls are being built. Each wall has 30 bricks in a single row and there are 50 rows in each wall. How many bricks will be used to make both walls?
Answer with step-by-step thinking:
Each brick wall needs 30 x 50 = 1500 bricks. Thus, the two walls need 1500 x 2 = 3000 bricks.
So the answer is 3000.