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Equal masses of three liquids A, B and C are at 12 C, 19 C and 28 C respectively. Mixing A and B gives 16 C; mixing B and C gives 23 C. What is the temperature when A and C are mixed?

1. 20.3 C
2. 22.2 C
3. 23 C
4. 24.8 C

Correct answer: 20.3 C

Solution

From the two given mixings, c_A:c_B = 3:4 and c_B:c_C = 5:4; combining gives the A+C mixture temperature about 20.3 C.

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