UKMT Grey Kangaroo, 2021

Algebra Difficulty 2.0 Junior Find the answer United Kingdom

When a jar is one-fifth filled with water, it weighs 560 g. When the same jar is four-fifths filled with water, it weighs 740 g. What is the weight of the empty jar?

(A) $60\text{ g}$ (B) $112\text{ g}$ (C) $180\text{ g}$ (D) $300\text{ g}$ (E) $500\text{ g}$

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