alleryUsing prime factorisation, √324 equals:
A12
B18
C21
D24
Answer & Solution
Correct answer: B. 18
We have 324 = 2² × 3⁴.
That is 324 = (2 × 3²)².
That is 324 = (2 × 9)².
So 324 = 18².
**So √324 = 18. (Pairs of primes give the square root: take one factor from each pair.)**
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