Sanket earns twice as much in the month of March as in each of the other months of the year. What part of his entire annual earnings was earned in March?

### Concept & Logic There are 12 months in a year. Let the earnings of a normal month be $x$. March is an exception where the earnings are $2x$. $$\text{Total Annual Earnings} = \text{Earnings in March} + \text{Earnings in remaining 11 months}$$ $$\text{Required Fraction} = \frac{\text{Earnings in March}}{\text{Total Annual Earnings}}$$ ### Step-by-Step Solution * **Define monthly earnings:** Let the earnings for each of the other 11 months = $x$ Therefore, earnings for March = $2x$ * **Calculate total yearly earnings:** $$\text{Total Earnings} = 2x + (11 \times x) = 13x$$ * **Calculate the proportion for March:** $$\text{Fraction for March} = \frac{2x}{13x} = \frac{2}{13}$$ ### Exam Strategy & Shortcut Assume a convenient value instead of $x$. Let the earnings of a regular month be ₹ 1. * Earnings for 11 months = ₹ 11 * Earnings for March = ₹ 2 * Total annual income = $11 + 2 = 13$ * March fraction = $\frac{2}{13}$ ### Common Pitfall Forgetting that March replaces one of the 12 months, leading to an incorrect total computation like $12x + 2x = 14x$, which gives a wrong fraction of $\frac{2}{14} = \frac{1}{7}$. ### Final Answer **Therefore, the correct answer is \frac{2}{13}.**