The total hardness value obtained from the complete analysis of a water sample is found to be 117 mg/l. The analysis further showed that the concentrations of all the three principal cations causing hardness are numerically same. Value of the carbonate hardness is 57 mg/l. Calculate the value of non-carbonate hardness is
1
50 mg/l
2
60 mg/l
3
6 mg/l
4
117 mg/l