Question

Two samples were weighed using different balance and the following data were obtained.
Sample #1=3.719 grams
Sample #2=0.42 gram
The total mass of the samples should be reported as :

• A. 4 grams
• B. 4.1 grams
• C. 4.139 grams
• D. 4.14 grams
• E. 4.140 grams

Answer 1

The correct option is D 4.14 grams

After rounding off to $2$ significant digits, weight of sample $1$ can be reported as $3.72$ grams. Therefore, total mass $=(3.72+0.42)=4.14$ grams.