Online Test — Arithmetic Progressions
10 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 10
medium
Which of the following sequences is an Arithmetic Progression?
2, 4, 8, 16, ...
5, 9, 13, 17, ...
1, 4, 9, 16, ...
3, 6, 12, 24, ...
Explanation: Check differences: 9-5=4, 13-9=4, 17-13=4 (constant)
Question 2 of 10
medium
For the AP: 10, 7, 4, 1, … , what is the common difference?
+3
-3
+4
-4
Explanation: 7-10 = -3, 4-7 = -3, so d = -3
Question 3 of 10
medium
What is the 10th term of the AP: 3, 8, 13, 18, …?
48
50
45
53
Explanation: a=3,d=5; \(a_{1}_{0}\)=3+9×5=3+45=48
Question 4 of 10
medium
Find the sum of first 15 terms of AP: 2, 7, 12, 17, …
555
560
565
570
Explanation: \(S_{1}_{5}\)=15/2[4+14×5]=7.5×76=570
Question 5 of 10
medium
Which term of the AP: 4, 9, 14, 19, … is 104?
20th
21st
22nd
23rd
Explanation: 104=4+(n-1)5 → 100=(n-1)5 → n-1=20 → n=21
Question 6 of 10
medium
The first term of an AP is 5 and the last term is 45. If there are 9 terms, find the sum.
200
225
250
275
Explanation: \(S_{9}\)=9/2(5+45)=4.5×50=225
Question 7 of 10
medium
Sum of first n natural numbers formula is:
n(n+1)/2
n(n-1)/2
\(n^{2}\)
n(n+2)/2
Explanation: Standard formula for 1+2+3+...+n = n(n+1)/2
Question 8 of 10
medium
Find the 8th term of AP: -5, -1, 3, 7, …
19
21
23
25
Explanation: a=-5,d=4; \(a_{8}\)=-5+7×4=-5+28=23
Question 9 of 10
medium
How many two-digit numbers are divisible by 6?
12
14
15
16
Explanation: Smallest=12, largest=96; 96=12+(n-1)6 → 84=(n-1)6 → n-1=14 → n=15
Question 10 of 10
medium
The sum of first 20 odd numbers is:
380
400
420
440
Explanation: Sum of first n odd numbers = \(n^{2}\) = \(20^{2}\) = 400