Question

Kevin and Amy are working on an experiment in the science lab. They start with 2.6 grams of oil and add water to get exactly 4.32 grams of solution. To find the amount of water added, they subtract the weight of the oil from the weight of the solution. Kevin calculates the difference to be 4.06 grams; Amy calculates it to be 1.72 grams. Who is correct, and why?

1) Amy is correct. Kevin did not regroup properly.
2) Kevin is correct. Amy did not line up the decimals correctly.
3) Kevin is correct. Amy did not regroup properly.
4) Amy is correct. Kevin did not line up the decimals correctly.

Answer 1

Amy is correct in calculating the amount of water added to the oil. The correct method is to subtract the weight of the oil from the weight of the solution, resulting in 1.72 grams.

Step-by-step explanation:

Kevin and Amy are trying to find out how much water was added to 2.6 grams of oil to make a solution that weighs 4.32 grams. The correct calculation to find the amount of water added is to subtract the weight of the oil from the weight of the solution. Therefore, the calculation should be 4.32 grams (weight of the solution) minus 2.6 grams (weight of the oil), which equals 1.72 grams. Amy's calculation is correct; Kevin did not subtract the numbers properly.

The correct answer is: 1) Amy is correct. Kevin did not regroup properly.