In a heat exchanger, 50000 \(\rm \frac{kg}{h}\) of hot water is cooled from 60°C to 40°C using the 40000 \(\rm \frac{kg}{h}\) of cold water entering at 5°C. If the specific heat of water is 4.18 \(\rm \frac{kJ}{kg-k}\), then the exit temperature will be:
1
20°C
2
50°C
3
30°C
4
40°C