Question

A whole number is added to a number with two digits after the decimal point. To ensure the answer is reasonable, how many digits should the sum have after the decimal point?

a) None
b) 1
c) 2
d) Infinitely many

Answer 1

The sum should have two digits after the decimal point, in accordance with the rule for significant figures in addition and subtraction.

Step-by-step explanation:

When a whole number is added to a number with two digits after the decimal point, the sum should also have two digits after the decimal point. This follows the rule of significant figures for addition and subtraction, where the result should be rounded to the same number of decimal places as the number with the least number of decimal places. Therefore, the sum should not have none, one, or infinitely many decimal places. Keeping to two decimal places ensures that the content loaded is reasonable and reflective of the precision of the original numbers given in the problem. For instance, if we consider the example 101.2 + 18.702, the proper sum would be 119.9 after rounding to the tenths place.