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UKMT Senior Mathematical Challenge, 2021

Algebra Difficulty 2.0 Junior Find the answer United Kingdom

Laura and Dina have a running race. Laura runs at constant speed and Dina runs $n$ times as fast where $n > 1$ . Laura starts $s$ m in front of Dina. What distance, in metres, does Dina run before she overtakes Laura?

(A) $\frac{ns}{n-1}$ (B) $ns$ (C) $\frac{s}{n-1}$ (D) $\frac{ns}{n+1}$ (E) $\frac{s}{n}$

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