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UKMT Intermediate Mathematical Challenge, 2012

Number theory Difficulty 1.0 Junior Find the answer United Kingdom

Auntie Fi's dog Itchy has a million fleas. His anti-flea shampoo claims to leave no more than 1% of the original number of fleas after use. What is the least number of fleas that will be eradicated by the treatment?

(A) $900\,000$ (B) $990\,000$ (C) $999\,000$ (D) $999\,990$ (E) $999\,999$

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