Tag: forming an arithmetic progression between two quantities a and b

Questions Related to forming an arithmetic progression between two quantities a and b

Find $(3^{3}-2^{3})+(5^{3}-4^{3})+(7^{3}-6^{3})+$ to $10$ terms.

  1. $4,670$

  2. $4,870$

  3. $4,800$

  4. $4,960$


Correct Option: A

The sum of the series $\dfrac{1}{1.2}-\dfrac{1}{2.3}+\dfrac{1}{3.4}-..\infty$ is

  1. $log _{e}2$

  2. $2log _{e}2$

  3. $log _{e}2-1$

  4. $log _{e}\dfrac{4}{e}$


Correct Option: A

Find the sum of  The first $15$ multiples of $8$

  1. The firs $40$ positive integers divisible by $(a)3(b)5(c)6.$

  2. All $3-$ digit natural numbers which are divisible by $13$.

  3. All $3-$ digit natural numbers, which area multiples of $11$.

  4. All $2-$ digit natural numbers divisible by $4$.


Correct Option: A

The sum of the series$\dfrac{1}{2!}+ \dfrac{1}{4!}+ \dfrac{1}{6!}+$ is

  1. $\dfrac{e^{2}-1}{2}$

  2. $\dfrac({e-1})^{2}{2e}$

  3. $\dfrac{e^{2}-1}{2e}$

  4. $\dfrac{e^{2}-2}{e}$


Correct Option: A

The sum of $\frac{1}{3\sqrt{1}+1\sqrt{3}}+\frac{1}{5\sqrt{3}+3\sqrt{5}}+\frac{1}{7\sqrt{5}+5\sqrt{7}}+...+\frac{1}{225\sqrt{223}+223\sqrt{225}}$ is 

  1. $\frac{123}{125}$

  2. $\frac{124}{125}$

  3. $\frac{14}{15}$

  4. $\frac{7}{15}$


Correct Option: A

A sum to $n$ terms of the series $\dfrac{3}{2^1 \cdot 2 \cdot 1} + \dfrac{4}{2^2 \cdot 3 \cdot 2} + \dfrac{5}{2^3 \cdot 4 \cdot 3} + \dfrac{6}{2^4 \cdot 5 \cdot 4} + ...$ is $S _n$ then

  1. $S _{10} = \dfrac{11263}{11264}$

  2. $S _{10} = \dfrac{22527}{11264}$

  3. If $n$ approaches $\infty, S _n$ approaches to $1$

  4. If $n$ approaches $\infty, S _n$ approaches to $2$


Correct Option: A

Sum to infinity of the $\dfrac{2}{3}$ - $\dfrac{5}{6}$ + $\dfrac{2}{3}$ - $\dfrac{11}{24}$+ ....... is 

  1. $\dfrac{4}{9}$

  2. $\dfrac{1}{3}$

  3. $\dfrac{2}{9}$

  4. none of these


Correct Option: A

what is the sum of $20.08, 20.008 , 20.088$ and $20.888 ?$

  1. $81.064$

  2. $81.604$

  3. $80.064$

  4. $80.888$


Correct Option: A

The sum of digits of all numbers from 1 to 300 is equal to 

  1. 3000

  2. 3003

  3. 3033

  4. none of these


Correct Option: A

the sum to infinity of the series
$1+\frac { 2 }{ 5 } +\frac { 6 }{ { 5 }^{ 2 } } +\frac { 10 }{ { 5 }^{ 3 } } +\frac { 14 }{ { 5 }^{ 4 } } +.....$ is

  1. $\frac { 4 }{ 7 } $

  2. $\frac { 5 }{ 4 } $

  3. $\frac { 7 }{ 4 } $

  4. $\frac { 6 }{ 5 } $


Correct Option: A