Directions: Each of the following questions consists of a question followed by three statements I, II and III. You have to study the question and the statements and decide which of the statement(s) is/are necessary to answer the question. What is Sumit's present salary? I. The salary increases every year by $12\%$. II. His salary at the time of joining was ₹ 3500. III. He had joined exactly 7 years ago.

### Concept & Formula Calculating a present value based on a past initial value that has increased at a consistent percentage rate requires the compound growth formula: $$A = P(1 + \frac{r}{100})^t$$ Where $A$ is the final amount (present salary), $P$ is the principal (joining salary), $r$ is the annual rate of increase, and $t$ is the time elapsed in years. ### Step-by-Step Solution * Target: Find Sumit's present salary ($A$). * To calculate $A$, we strictly need the values for the three missing variables: $P$, $r$, and $t$. * Evaluate Statement I: Provides the annual rate of increase, $r = 12\%$. (Insufficient alone) * Evaluate Statement II: Provides the initial joining salary, $P = 3500$. (Insufficient alone) * Evaluate Statement III: Provides the time period elapsed, $t = 7$ years. (Insufficient alone) * Calculation / Deduction: * Combining all three statements gives us all the necessary components for the formula: * $$A = 3500 \times (1 + 0.12)^7$$ * Because each statement provides exactly one indispensable piece of the mathematical puzzle, all three statements are mandatory to calculate the final answer. ### Exam Strategy & Shortcut For standard compound interest or population/salary growth problems, immediately list the required formula variables ($P$, $r$, $t$, $A$). The question asks for $A$. Scan the statements: I gives $r$, II gives $P$, III gives $t$. Since all three inputs are required, the answer is "All three". Do not waste time attempting to calculate $1.12^7$. ### Common Pitfall Attempting to solve the arithmetic exactly. Data sufficiency questions test your logical capacity to identify if a solution exists, not your ability to perform complex exponential calculations by hand. Recognizing the formula is enough. ### Final Answer **Therefore, the correct answer is All I, II and III.**