✓ Board-verified↻ asked 3×
Mathematics · 2022 · 2 marks
CBSE 2022 · Region 2 · Set 1 · Q6
Find the sum of first $\displaystyle 20$ terms of an A.P. whose $\displaystyle \mathrm{n}^{\text {th }}$ term is given as $\displaystyle \mathrm{a}_{\mathrm{n}}=5-2 \mathrm{n}$.
Marking-scheme solution
\[\begin{array}{l}
a_{1}=5-2=3 \\
a_{20}=5-40=-35 \\
S_{20}=\frac{20}{2}(3-35)=-320
\end{array}
\]SECTION-B
More from Arithmetic Progressions
- Cable cars at hill stations are one of the major tourist attractions. On a hill station, the length of cable…2025 · asked 3×
- In order to organise, Annual Sports Day, a school prepared an eight lane running track with an integrated…2025 · asked 3×
- In Mathematics, relations can be expressed in various ways. The matchstick patterns are based on linear…2022 · asked 3×
- If the sum of the first n terms of an A.P be 3 n^2+n and its common difference is 6, then its first term is2023 · asked 3×
- The sum of first and eighth terms of an A.P. is 32 and their product is 60. Find the first term and common…2024 · asked 3×
- Assertion: Common difference of the AP: 5,1,-3,-7, … is 4. Reason (R): Common difference of the AP: a 1, a 2,…2025 · asked 3×
- Find two consecutive negative integers, sum of whose squares is 481.2026 · asked 3×
- A faster train takes one hour less than a slower train for a journey of 200 km. If the speed of the slower…2026 · asked 3×
CBSE Class 10 Mathematics past-paper question from the 2022board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.