ABCD is a square of side 400 m. E and F are points 200 and 300 m away from corner D. Two persons starting from E and F and moving away from D, meet at B. Where would they meet if they were to travel towards D. (Give the distance of the meeting point from D, in m.)
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Moving away from D, the person from E covers $$200 + 400 = 600\text{ m}$$ to reach B and the person from F covers $$100 + 400 = 500\text{ m}$$, in the same time, so their speeds are in the ratio $$6 \colon 5$$. Moving towards D, the path between them via D is $$200 + 300 = 500\text{ m}$$, and the person from E covers $$\frac{6}{11} \times 500 \approx 272.7\text{ m}$$ of it. That takes him past D and $$\frac{800}{11} \approx 72.73\text{ m}$$ along DC, which is where they meet.