Final answer:
Some quantities can be determined exactly, such as the number of seconds in an hour (3600 seconds) and the number of grams in 3 kilograms (3000 grams), while others, like the number of pages in a book, can be counted if the book is present, and the number of grams in one's weight must be measured and is subject to uncertainty.
Step-by-step explanation:
The question asks to indicate whether certain quantities can be determined exactly or must be measured with some degree of uncertainty. For each item listed:
- (a) The number of seconds in an hour can be determined exactly because there are 60 seconds in a minute and 60 minutes in an hour, thus 3600 seconds in an hour.
- (b) The number of pages in a book is a countable quantity. If the book is in front of you and is already printed, then the number of pages can be counted exactly.
- (c) The number of grams in your weight must be measured with some uncertainty as biological weight can fluctuate, and scales may have varying degrees of precision.
- (d) The number of grams in 3 kilograms can be determined exactly because there are 1000 grams in a kilogram, so there are exactly 3000 grams in 3 kilograms.