The alkalinity and hardness of a water sample are 250 mg/l

The alkalinity and hardness of a water sample are 250 mg/l and 350 mg/l as CaCO₃, respectively. The water has

1. 350 mg/l carbonate hardness and zero non-carbonate hardness.
2. 250 mg/l carbonate hardness and zero non-carbonate hardness.
3. 250 mg/l carbonate hardness and 350 mg/l noncarbonate hardness.
4. 250 mg/l carbonate hardness and 100 mg/l noncarbonate hardness.

The lower of alkalinity and hardness is carbonate value.
This, carbonate hardness = 250 mg/l.
Non-carbonate hardness = 350 – 250 = 100 mg/l