Which of the following numbers are not perfect cubes?
(i) 216                  (ii) 128           (iii) 1000           (iv) 100(v) 46656

Explanation

To determine which of the given numbers are not perfect cubes, we will perform prime factorization for each number and check if all prime factors can be grouped into triplets.

### Step-by-Step Solution:

1. **Check 216:**
- Prime factorization:
- 216 = 2 × 2 × 2 × 3 × 3 × 3
- This can be written as \( 2^3 \times 3^3 \).
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