Question

Consider the addition: $0.04658+4.342+2.32+5.6$.

The answer must contain only $x$ significant figures. What is the value of $x$?

• A. $3$
• B. $4$
• C. $2$
• D. $5$

Answer 1

The correct option is A $3$

When combining measurements with different degrees of accuracy and precision, the accuracy of the final answer can be no greater than the least accurate measurement.

The result of addition cannot have more digits to the right of the decimal point than either of the original numbers.

The sum of $0.04658+4.342+2.32+5.6$ is $12.30858$.

But one of the numbers to be added has only one decimal point.

Hence, the result is reported with only one decimal point which is 12.3.

In other words, the result contains 3 significant figures.

Hence the correct option is A.