Quantitative Aptitude

Number Series

2,662 Questions
All First differences and arithmetic progressions 812 Successive multiplication or division 429 Step-wise calculations 349 Squares and cubes based 338 Separate alternate positions 241 Inter-term operations 144 Mixed-operation rules 138 Unconventional pattern solving 74 Fractional and decimal operations 60 Prime number based 54 Digit operations 23

Number Series Questions

Multiple choice

Check if the series is an AP. Find the common difference $d$ and write three more terms of the the following series. $2, 4, 8, 16,....$
  1. Common difference: $2$ and Other three terms are: $32, 64, 128$
  2. Common difference: $4$ and Other three terms are: $24, 32, 40$
  3. Common difference: $8$ and Other three terms are: $20, 24, 28$

  4. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The series 2, 4, 8, 16 is a geometric progression (ratio 2), not an arithmetic progression (AP). Therefore, there is no common difference d.

Multiple choice

Check if the series is an A.P. Find the common difference $d$ and write three more terms of the the following series. $2,\displaystyle\frac{5}{2}$, $3,\displaystyle\frac{7}{2}, ...$
  1. $a=2$; $d=\dfrac{1}{2}$; other terms $4,$ $\dfrac{9}{2},5$ 
  2. $a=3$; $d=\dfrac{1}{2}$; other terms $6, 8, 10$
  3. $a=2$; $d=\dfrac{3}{2}$; other terms $7, 8, 15$
  4. $a=3$; $d=\dfrac{3}{2}$; other terms $4, 5, 15$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The series is 2, 2.5, 3, 3.5. Common difference d = 0.5. Next three terms are 4, 4.5, 5.

Multiple choice

The first term of an infinite G.P. is $1$ and any term is equal to the sum of all the succeeding terms. Find the series.
  1. $1, 2, 4, 8, ......$
  2. $1,\, \displaystyle {\frac{1}{3},\, \frac{1}{9},\, \frac{1}{27},\, .....}$
  3. $1,\, \displaystyle {\frac{1}{4},\, \frac{1}{8}}, .....$
  4. $1,\, \displaystyle {\frac{1}{2},\, \frac{1}{4},\, \frac{1}{8},\, .....}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

For a G.P. with first term a=1 and common ratio r, the sum of succeeding terms is a*r / (1-r). Setting 1 = r / (1-r) gives 1-r = r, so 2r = 1, r = 1/2. The series is 1, 1/2, 1/4, 1/8, ...