CAT (QA) PYQs

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 $X+Y$.

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

Bank $A$ offers $6 \%$ interest rate per annum compounded half yearly. Bank $B$ and Bank Coffer simple interest but the annual interest rate offered by Bank $C$ is twice that of Bank $B$. Raju invests a certain amount in Bank B for a certain period and Rupa invests $₹ 10,000$ in Bank $C$ for twice that period. The interest that would accrue to Raju during that period is equal to the interest that would have accrued had he invested the same amount in Bank $A$ for one year. The interest accrued, in INR, to Rupa is