The Correct Option is C
Solution and Explanation
Approach: Don't solve a quadratic at all. CAT gives you four clean rate options, so just test them by tracking the outstanding balance year by year and check which one clears the loan exactly.
Step 1: The rule: each year the balance grows by the rate, then the instalment is subtracted. The correct rate leaves a zero balance after the second payment.
Step 2: Test $r = 8\%$. After year 1 the loan becomes $1000 \times 1.08 = 1080$. Pay Rs 530, leaving $1080 - 530 = 550$.
Step 3: That Rs 550 grows for the second year: $550 \times 1.08 = 594$. Pay the second instalment of Rs 594, leaving $594 - 594 = 0$.
Step 4: The balance vanishes exactly, so $8\%$ is correct. (Quick sanity check: at $7\%$, $1000 \times 1.07 - 530 = 540$, then $540 \times 1.07 = 577.8 \ne 594$, so it fails.)
Final answer: $8\%$.