$1.4\; g$ of an organic compound was digested according to Kjeldahl's method and the ammonia evolved was absorbed in $60 \;mL$ of $M/10\; H_2 SO_4$ solution. The excess sulphuric acid required $20\; mL$ of $M/10 \;NaOH$ solution for neutralization. The percentage of nitrogen in the compound is :
