alleryWhat is the smallest natural number by which 1620 must be DIVIDED so that the quotient is a perfect square?
A3
B5
C15
D45
Answer & Solution
Correct answer: B. 5
1620 = 2² × 3⁴ × 5. The prime 5 appears with an odd exponent (1).
Dividing by 5 leaves 2² × 3⁴ = (2 × 9)² = 324 = 18², a perfect square.
**So the smallest divisor is 5.**
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