Answer :
Final answer:
To determine the number of significant digits in the answer, align the decimal points and subtract. The answer, 36.6, should have the same number of decimal places as the number with the most decimal places.
Explanation:
To determine the number of significant digits in the answer, we need to consider the given values. The number 49 has two significant digits, while 12.4 has three significant digits. When subtracting 12.4 from 49, we need to align the decimal points and then subtract:
49.0
-12.4
_____
36.6
Since the decimal point is present in both numbers, the answer should have the same number of decimal places as the number with the most decimal places. In this case, 12.4 has one decimal place, so the answer should be expressed as 36.6, which has one decimal place.