Back to Maths on Exam Trends
Arithmetic Progression
High trendapprox. 5 marksSections A/B/C/D — a 1-mark nth-term or common-difference MCQ, plus a 3–5 mark sum or word problem.
CBSE 2027 — dates, rules and official papers →Ask the tutor1State the values of a, d and n explicitly and write the formula before substituting — boards award method marks for the correct formula even when the final arithmetic slips.
Notesformulae · proofs · mind-map — one view
Learn the 4 conceptsteach yourself first, then practise each
Common difference d = aₙ − aₙ₋₁ (test for an AP)1–2 marks Visual
Confirm a list is an AP and read off a and d before anything else.
nth term aₙ = a + (n−1)d1–3 marks Visual
Find any term, the number of terms, or set up an equation from a given term.
Sum of first n terms Sₙ = n/2[2a + (n−1)d]2–5 marks Visual
Total the first n terms straight from a, d and n.
Sum with last term Sₙ = n/2(a + l)2–3 marks Visual
Add terms quickly when the last term l is known instead of d.
When you’re ready — practise or test the whole topic