Vidaara.orgClass 11 · Mathematics
CodeVID-M11-08-AP-01
Arithmetic Progression & Mean — Assignment
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Section A carries 1 mark each, Section B 2 marks, Section C 3 marks and Section D 5 marks.
- Show all working for Sections B, C and D. Only final answers are given at the end — for full solutions, raise your doubts with your teacher.
Section A — Multiple Choice Questions
5 × 1 = 5 marks
1.
The $n$th term of an AP is:
- A.$a+nd$
- B.$a+(n-1)d$
- C.$ar^{n-1}$
- D.$nd$
2.
The common difference of $3,7,11,\dots$ is:
- A.$3$
- B.$4$
- C.$7$
- D.$1$
3.
The sum of the first $n$ natural numbers is:
- A.$n^2$
- B.$\tfrac{n(n+1)}{2}$
- C.$\tfrac{n(n-1)}{2}$
- D.$n!$
4.
The arithmetic mean of $4$ and $10$ is:
- A.$6$
- B.$7$
- C.$5$
- D.$14$
5.
The $10$th term of $1,3,5,\dots$ is:
- A.$17$
- B.$19$
- C.$21$
- D.$20$
Section B — Short Answer (2 marks)
4 × 2 = 8 marks
6.
Find the $15$th term of the AP $2,5,8,\dots$
7.
Find the sum of the first $20$ natural numbers.
8.
Find the common difference if $a=3$ and $a_5=19$.
9.
Insert the arithmetic mean between $7$ and $17$.
Section C — Short Answer (3 marks)
4 × 3 = 12 marks
10.
Find the sum of the first $10$ terms of the AP $2,5,8,\dots$
11.
Which term of the AP $5,8,11,\dots$ is $50$?
12.
Find the AP whose $3$rd term is $7$ and $7$th term is $19$.
13.
Find the sum of the first $12$ odd natural numbers.
Section D — Long Answer (5 marks)
2 × 5 = 10 marks
14.
The sum of three numbers in AP is $27$ and their product is $405$. Find the numbers.
15.
How many terms of the AP $9,17,25,\dots$ must be taken to give a sum of $636$?
Answer Key
Section A — Multiple Choice Questions
- (B) $a+(n-1)d$
- (B) $4$
- (B) $\tfrac{n(n+1)}{2}$
- (B) $7$
- (B) $19$
Section B — Short Answer (2 marks)
- $44$.
- $210$.
- $4$.
- $12$.
Section C — Short Answer (3 marks)
- $155$.
- The $16$th term.
- $1,4,7,10,\dots$ ($a=1,d=3$).
- $144$.
Section D — Long Answer (5 marks)
- $3,9,15$.
- $12$ terms.
Generated by Vidaara.org · Assignment VID-M11-08-AP-01 · vidaara.org