Rehana went to a bank to withdraw ₹ $\displaystyle 2,000$ . She asked the cashier to give her ₹ $\displaystyle 50$ and ₹ $\displaystyle 100$ notes only. Rehana got $\displaystyle 25$ notes in all. Find how many notes of ₹ $\displaystyle 50$ and ₹ $\displaystyle 100$ did she receive.

Let number of ₹$\displaystyle 50$ notes \(\displaystyle =\mathrm{x}\) and number of ₹$\displaystyle 100$ notes \(\displaystyle =\mathrm{y}\) \[\begin{aligned} & \text { Here } \mathrm{x}+\mathrm{y}=25 \text {-----(i) } \\ & \qquad 50 \mathrm{x}+100 \mathrm{y}=2000 \text { or } \mathrm{x}+2 \mathrm{y}=40 \quad \text {-------(ii) } \end{aligned} \] Solving eq.(i) and eq.(ii), we get \[x=10 \text { and } y=15 \] Therefore $\displaystyle 10$ notes of ₹$\displaystyle 50$ and $\displaystyle 15$ notes of ₹$\displaystyle 100$ are received.