Chemistry · Some Basic Concepts of Chemistry

According to the convention for rounding off numbers, if the rightmost digit to be removed is \( 5 \), followed by no other digits, which of the following pairs are correctly rounded off to two significant figures?

1. \( 6.35 \rightarrow 6.3 \) and \( 6.25 \rightarrow 6.3 \)
2. \( 6.35 \rightarrow 6.3 \) and \( 6.25 \rightarrow 6.2 \)
3. \( 6.35 \rightarrow 6.4 \) and \( 6.25 \rightarrow 6.3 \)
4. \( 6.35 \rightarrow 6.4 \) and \( 6.25 \rightarrow 6.2 \)