Find the number of significant figures in the following numbers.
(i) 6729 , (ii) 0.024 ,(iii) 6.0023 , (iv) `2.520 xx 10^7` , (v) 0.08240
(vi) 4200 , (vii) `4.57xx10^8` , (viii) 91.000

Explanation

To find the number of significant figures in the given numbers, we will analyze each number based on the rules of significant figures.

### Step-by-Step Solution:

**(i) 6729**
- All digits are non-zero.
- Therefore, the number of significant figures = 4.

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