UKMT Grey Kangaroo, 2018

Algebra Difficulty 2.0 Junior Find the answer United Kingdom

Ruth and Sarah decide to have a race. Ruth runs around the perimeter of the pool shown in the diagram while Sarah swims lengths of the pool. Ruth runs three times as fast as Sarah swims. Sarah swims six lengths of the pool in the same time Ruth runs around the pool five times. How wide is the pool?

(A) $25$ m (B) $40$ m (C) $50$ m (D) $80$ m (E) $180$ m

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