100 ml of a sample of water required 15 ml of 0.01 M EDTA for titration using Eriochrome Black-T as an indicator. In another experiment, 100 ml of the same sample was boiled to remove the temporary hardness. The precipitate was removed and the cold solution required 8 ml of 0.01 M EDTA using Eriochrome Black T as an indicator. Calculate the total hardness, permanent hardness, and temporary hardness in mg/litre of CaCO₃ equivalent hardness of water.

100 ml of boiled water sample:
- Determination of permanent hardness: 8 ml of 0.01 M EDTA = 8 mg of CaCO₃ equivalent hardness.
- Hardness of hard water = 8 mg/1000 ml of water sample x 1000 = 80 mg/litre.

Temporary hardness:
Total hardness - Permanent hardness = 150 mg/litre - 80 mg/litre = 70 mg/litre.