CAT (QA) PYQs

A person invested a certain amount of money at $10\%$ annual interest, compounded half-yearly. After one and a half years, the interest and principal together became Rs $18522$. The amount, in rupees, that the person had invested is

Gopal borrows Rs. $X$ from Ankit at $8 \%$ annual interest. He then adds Rs. $Y$ of his own money and lends Rs. $X+Y$ to Ishan at $10 \%$ annual interest. At the end of the year, after returning Ankit's dues, the net interest retained by Gopal is the same as that accrued to Ankit. On the other hand, had Gopal lent Rs. $X+2Y$ to Ishan at $10 \%$, then the net interest retained by him would have increased by Rs. $150$. If all interests are compounded annually, then find the value of $X+Y$.

Nitu has an initial capital of Rs. $20,000$. Out of this, she invests Rs. $8,000$ at $5.5\%$ in bank $A$, Rs. $5,000$ at $5.6\%$ in bank $B$ and the remaining amount at $x \%$ in bank $C$ , each rate being simple interest per annum. Her combined annual interest income from these investments is equal to $5 \%$ of the initial capital. If she had invested her entire initial capital in back $C$ alone, then her annual interest income, in rupees, would have been