55. Exemplar exercise problem XVI

Kanika was given her pocket money on Jan $1$st, $2008$. She puts $₹1$ on Day $1$, $₹2$ on Day $2$, $₹3$ on Day $3$, and continued doing so till the end of the month, from this money into her piggy bank. She also spent $₹204$ of her pocket money, and found that at the end of the month she still had $₹100$ with her. How much was her pocket money for the month?

 

Kanika's pocket money for the month $₹$.