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UKMT Grey Kangaroo, 2016

Algebra Difficulty 2.0 Junior Find the answer United Kingdom

Theo's watch is $10$ minutes slow, but he believes it is $5$ minutes fast. Leo's watch is $5$ minutes fast, but he believes it is $10$ minutes slow. At the same moment, each of them looks at his own watch. Theo thinks it is $12{:}00$ . What time does Leo think it is?

(A) $11{:}30$ (B) $11{:}45$ (C) $12{:}00$ (D) $12{:}30$ (E) $12{:}45$

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