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A-LevelMathematicsDifferential equationsOct/Nov 2025Paper 3 Q109 Marks

The diagram shows a tank for holding water. The tank is in the shape of a cube of side 50 cm. At time t seconds, the depth of water in the tank is hcm. Water is poured into the tank at a rate of 5000 cm³ s⁻¹. Water pours out of the tank through a hole in the bottom at a rate proportional to h². When h = 20, the depth of the water is increasing at a rate of 0.4 cms⁻¹. [Figure 10.1]

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About This A-Level Mathematics Question

This structured question appeared in the Cambridge A-Level Mathematics (9709) Oct/Nov 2025 examination, Paper 3 Variant 2. It tests the topic of Differential equations and is worth 9 marks.

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