Progressions(Quantitative Aptitude ) Questions and answers for exam Preparation

Question 1. If Sn denotes the sum of the first r terms of an A.P. Then, S3n : (S2n – Sn) is

n
3n
3
None of these

Explanation:-

Answer: Option C. -> 3

Question 2. If $$\frac{1}{{x + 2}},$$ $$\frac{1}{{x + 3}},$$ $$\frac{1}{{x + 5}}$$ are in A.P. then x = ?

5
3
1
2

Explanation:-

Answer: Option C. -> 1

Question 3. If $$\frac{{5 + 9 + 13 + ...\,{\text{to}}\,n\,{\text{terms}}}}{{7 + 9 + 11 + ...\,{\text{to}}\,\left( {n + 1} \right)\,{\text{terms}}}}$$ $$ = \frac{{17}}{{16}},$$ then n = ?

8
7
10
11

Explanation:-

Answer: Option B. -> 7

Question 4. If the first term of an A.P. is a and nth term is b, then its common difference is

$$\frac{{b - a}}{{n + 1}}$$
$$\frac{{b - a}}{{n - 1}}$$
$$\frac{{b - a}}{n}$$
$$\frac{{b + a}}{{n - 1}}$$

Explanation:-

Answer: Option B. -> $$\frac{{b - a}}{{n - 1}}$$

Question 5. The common difference of the A.P. is $$\frac{1}{{2q}},$$ $$\frac{{1 - 2q}}{{2q}},$$ $$\frac{{1 - 4q}}{{2q}},$$ . . . . is

-1
1
q
2q

Explanation:-

Answer: Option A. -> -1

Question 6. The first three terms of an A.P. respectively are 3y – 1, 3y + 5 and 5y + 1. Then, y equals

-3
4
5
2

Explanation:-

Answer: Option C. -> 5

Question 7. If 7th and 13th terms of an A.P. be 34 and 64 respectively, then its 18th term is

87
88
89
90

Explanation:-

Answer: Option C. -> 89

Question 8. If the sum of it terms of an A.P. is 2n2 + 5n, then its nth term is

4n - 3
3n - 4
4n + 3
3n + 4

Explanation:-

Answer: Option C. -> 4n + 3

Question 9. In an AP, Sp = q, Sq = p and S denotes the sum of first r terms. Then, Sp+q is equal to

0
– (p + q)
p + q
pq

Explanation:-

Answer: Option C. -> p + q

Question 10. If the sum of first n even natural number is equal to k times the sum of first n odd natural numbers, then k =

$$\frac{1}{n}$$
$$\frac{{n - 1}}{n}$$
$$\frac{{n + 1}}{{2n}}$$
$$\frac{{n + 1}}{n}$$

Explanation:-

Answer: Option D. -> $$\frac{{n + 1}}{n}$$