First let us get the sum of the numbers.
2.1 g + 33.566 g + 12.22 g = 47.886 g
Now to get the proper degree of precision, the amount of
decimal places should be equal to the least decimal places of the numbers that
were added. In this case, 2.1 g has the least number of decimal places which is
equal to 1, hence the correct answer is:
47.9 g
