Express the result as the percentage of nitrogen (N) contained in the fertiliser as received for analysis.
Variant (a): N% = (50−A) × 1.12
Variant (b): N% = (50−A) × 1.12
Variant (c): N% = (35-A) × 1.40
Where A = millilitres of sodium or potassium hydroxide used for the titration.