Achemist weighed three separate test samples at 0.17 gram, 0.204 gram, and 2.3 grams. what is the total weight of the three samples?

The word "total" tells you that we have to add:
0.17 g+ 0.204 g+ 2.3 g= 2.674 g.

Since 2.3 (g) has the least significant figures (which is 2) among the three numbers, the answer should also have 2 significant figures.

The final answer is 2.7 g.

Hope this helps~

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