Bath

In the bath is 30 liters of hot water. Then added 36 liters of cold water at temperature of 19 °C decreased temperature of water to 41 °C.

What was the initial temperature of the hot water?

Correct answer:

t =  67.4 °C

Step-by-step explanation:

$$\begin{gathered} 30t+36\cdot 19=(30+36)\cdot 41 \\ t=67.4\text{°C} \end{gathered}$$

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