Mixed hot water with a volume of 3 liters taken at a temperature of 100 degrees and cold water with a volume of 2 liters

Mixed hot water with a volume of 3 liters taken at a temperature of 100 degrees and cold water with a volume of 2 liters at a temperature of 20 degrees. Determine the temperature of the mixture.

The amount of heat received by cold water is equal to the amount of heat given off by hot water. Let’s assume that 1 liter of water has a mass of 1 kg.
Then you get the following equation:
c * 3 * (100 – t) = c * 2 * (t – 20);
Let’s transform and solve:
300 – 3t = 2t – 40;
5t = 340;
t = 68;
Answer: 68 degrees.