Mathematics

Mathematics

Problem

A trainee teacher receives a salary that starts at ₹18 000₹18\,000 in April and increases by ₹750₹750 every month. The financial year is taken from April to the following March (12 months in all). a. (i) Express the salary for the nnth month (April taken as n=1n=1) in terms of nn. b. (ii) In which month of the financial year will the salary first exceed ₹24 000₹24\,000? c. (iii) For how many months in the same financial year will the salary remain below ₹30 000₹30\,000? d. (iv) Calculate the total salary drawn by the trainee during this financial year.
Intuitive explanation

This is an arithmetic sequence problem disguised as a salary question. Your salary forms a sequence where each month adds a constant amount (₹750₹750) to the previous month—that's the defining feature of arithmetic growth. To find total earnings over the year, you'll use the arithmetic series formula, which sums all 12 terms efficiently rather than adding month-by-month. The key insight is recognizing the pattern and applying the right formula for the sum.

Intuitive explanation

This is an arithmetic sequence problem disguised as a salary question. Your salary forms a sequence where each month adds a constant amount (₹750₹750) to the previous month—that's the defining feature of arithmetic growth. To find total earnings over the year, you'll use the arithmetic series formula, which sums all 12 terms efficiently rather than adding month-by-month. The key insight is recognizing the pattern and applying the right formula for the sum.

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