This is question 101 from "GMAT Official Guide 2019 Quantitative Review".
"An open box in the shape of a cube measuring 50 centimeters on each side is constructed from plywood. If the plywood weighs 1.5 grams per square centimeter, which of the following is closest to the total weight, in kilograms, of the plywood used for the box? (1 kilogram = 1,000 grams)" The answer is 19 kilograms
1. First thing I did was: (1.5 grams/ cm squared) times (50 cm/ 1 side) times (4 sides/ 1) times (1 kilogram/1000gram) and all of that equals 0.3 kilo
2. 50 times 4 to get 2000cm. 2000cm times (1.5grams/cm squared) times (1 kilo/1000grams) and all of that equals 3kilo
3. 50 cm times 50 cm to get area of 2500 cm squared. 2500 times 1.5 to get 3750 grams. 3750 grams divided by 1000 to get 3.75 kg
4. Then I did 50 times 50 to get 2500 cm squared (the area). Then I did 2500 times 1.5 to get 3750. 3750 divided by 1000 grams gets you 3.75 kilo. 3.75 times 6 equals 22.50kilograms.
Which path is closest to being right and why??
"An open box in the shape of a cube measuring 50 centimeters on each side is constructed from plywood. If the plywood weighs 1.5 grams per square centimeter, which of the following is closest to the total weight, in kilograms, of the plywood used for the box? (1 kilogram = 1,000 grams)" The answer is 19 kilograms
1. First thing I did was: (1.5 grams/ cm squared) times (50 cm/ 1 side) times (4 sides/ 1) times (1 kilogram/1000gram) and all of that equals 0.3 kilo
2. 50 times 4 to get 2000cm. 2000cm times (1.5grams/cm squared) times (1 kilo/1000grams) and all of that equals 3kilo
3. 50 cm times 50 cm to get area of 2500 cm squared. 2500 times 1.5 to get 3750 grams. 3750 grams divided by 1000 to get 3.75 kg
4. Then I did 50 times 50 to get 2500 cm squared (the area). Then I did 2500 times 1.5 to get 3750. 3750 divided by 1000 grams gets you 3.75 kilo. 3.75 times 6 equals 22.50kilograms.
Which path is closest to being right and why??