Final answer:
The numbers 6.1, 6.3, 6.2, and 6.4 each have two significant figures.
Step-by-step explanation:
When determining the number of significant figures in a decimal number, count all the digits from the first non-zero digit to the end. For whole numbers, count all the digits except for trailing zeros.
- Part A: 6.1 has two significant figures.
- Part B: 6.3 has two significant figures.
- Part C: 6.2 has two significant figures.
- Part D: 6.4 has two significant figures.