- Home
- Quantitative
- English
- Reasoning
- IT Officer
- Programming
-
Computer
- Computer Awareness Questions Answers - Set 1
- Computer Awareness Questions Answers - Set 2
- Important Abbreviations Computer Awareness Questions Answers
- Important File Extensions Questions Answers
- Computer System Architecture Questions Answers
- MS Office Questions Answers
- MS Excel Questions Answers
- MS PowerPoint Questions Answers
-
GK
- Geography Questions Answers
- Indian History Questions Answers
- World History Questions Answers
- Indian Economy Questions Answers
- Indian Polity and Constitution
- Physics Questions Answers
- Chemistry Questions Answers
- Biology Questions Answers
- First In India
- First In World
- Longest and Largest
- Books and Authors
- Important Days of year
- Countries and Capitals
- Inventions and Inventors
-
Current Affairs
- Current Affairs
- Current Affairs 2018
- Current Affairs 2018 - 2019 PDF
- Current Affairs August 2019
- Current Affairs July 2019
- Current Affairs June 2019
- Current Affairs May 2019
- Current Affairs April 2019
- Current Affairs March 2019
- Current Affairs February 2019
- Current Affairs January 2019
- Current Affairs December 2018
- Current Affairs November 2018
- Current Affairs October 2018
- Current Affairs September 2018
- Govt Jobs
- Exams
- Online Quiz
- You are here
- Home
- Quantitative Aptitude
- Arithmetic Aptitude Questions Answers
- Surds and Indices Questions Answers
- Aptitude Question
- Current Affairs 2019
- Current Affairs 2018
- Current Affairs December 2018
- Current Affairs November 2018
- Current Affairs October 2018
- Current Affairs September 2018
- Current Affairs August 2018
- Current Affairs July 2018
- Current Affairs June 2018
- Current Affairs May 2018
- Current Affairs April 2018
- Current Affairs March 2018
- Current Affairs February 2018
- Current Affairs January 2018
- Current Affairs 2018
- Current Affairs PDF
- Current Affairs PDF Download
- Current Affairs July 2019 PDF
- Current Affairs June 2019 PDF
- Current Affairs May 2019 PDF
- Current Affairs April 2019 PDF
- Current Affairs March 2019 PDF
- Current Affairs February 2019 PDF
- Current Affairs January 2019 PDF
- Current Affairs December 2018 PDF
- Current Affairs November 2018 PDF
- Current Affairs October 2018 PDF
- Current Affairs September 2018 PDF
- Current Affairs August 2018 PDF
- Current Affairs July 2018 PDF
- Current Affairs June 2018 PDF
- Current Affairs May 2018 PDF
- Current Affairs April 2018 PDF
- Current Affairs March 2018 PDF
- Current Affairs February 2018 PDF
- Current Affairs January 2018 PDF
Question Detail
\begin{aligned}
\left(25 \right)^{7.5} \times \left(5 \right)^{2.5} \div \left(125 \right)^{1.5} = 5^?
\end{aligned}
- 9.7
- 11.5
- 12
- 13
Answer: Option D
Explanation:
Lets assume,
\begin{aligned}
\left(25 \right)^{7.5} \times \left(5 \right)^{2.5} \div \left(125 \right)^{1.5} = 5^x \\
\text{then, } \frac{ \left( 5^2 \right)^{7.5} \times \left(5 \right)^{2.5} }{\left(5^3 \right)^{1.5} } = 5^x \\
=> \text{then, } \frac{ \left( 5^{15} \right) \times \left(5^{2.5} \right) }{\left(5^{4.5} \right) } = 5^x \\
=> 5^x = 5^{15 + 2.5 - 4.5} \\
=> 5^x = 5^{13} \\
\text{Hence, } x = 13
\end{aligned}
1. \begin{aligned} \text{If } 5^{(a + b)} = 5 \times 25 \times 125 ,\\ \text{what is }(a + b)^2
\end{aligned}
- 25
- 28
- 36
- 44
Answer: Option C
2. \begin{aligned}
\text{If }x = \left(8 + 3\sqrt{7}\right),\text{ what is the value of }\\\left(\sqrt{x} - \dfrac{1}{\sqrt{x}}\right)?
\end{aligned}
- \begin{aligned} \sqrt{13} \end{aligned}
- \begin{aligned} \sqrt{14} \end{aligned}
- \begin{aligned} \sqrt{15} \end{aligned}
- \begin{aligned} \sqrt{16} \end{aligned}
Answer: Option B
Explanation:
\begin{align}&\left(\sqrt{x} - \dfrac{1}{\sqrt{x}}\right)^2\\\\
&= x - 2 + \dfrac{1}{x}\\\\
&= x + \dfrac{1}{x} - 2 \\\\
&= \left(8 + 3\sqrt{7}\right) + \dfrac{1}{\left(8 + 3\sqrt{7}\right)} - 2 \\\\
&= \left(8 + 3\sqrt{7}\right) + \dfrac{\left(8 - 3\sqrt{7}\right)}{\left(8 + 3\sqrt{7}\right)\left(8 - 3\sqrt{7}\right)} - 2 \\\\
&= \left(8 + 3\sqrt{7}\right) + \dfrac{\left(8 - 3\sqrt{7}\right)}{8^2 - \left(3\sqrt{7}\right)^2} - 2 \\\\
&= \left(8 + 3\sqrt{7}\right) + \dfrac{\left(8 - 3\sqrt{7}\right)}{64 - 63} - 2 \\\\
&= \left(8 + 3\sqrt{7}\right) + \dfrac{\left(8 - 3\sqrt{7}\right)}{1} - 2 \\\\
&= 8 + 3\sqrt{7} + 8 - 3\sqrt{7} - 2 \\\\
&= 14 \\\\
&\text{as }\left(\sqrt{x} - \dfrac{1}{\sqrt{x}}\right)^2 = 14\\\\
&\text{so ,}\left(\sqrt{x} - \dfrac{1}{\sqrt{x}}\right) = \sqrt{14}\end{align}
3. \begin{aligned}
\text{If } 3^{x-y} = 27 \text{ and } 3^{x+y} = 243, \\
\text{ then find the value of x }
\end{aligned}
- 1
- 2
- 3
- 4
Answer: Option D
Explanation:
\begin{aligned}3^{x-y} = 27 = 3^3 <=> x-y = 3 \text{... (i)}\\
3^{x+y} = 243 = 3^5 <=> x+y = 5 \text{... (ii)} \\
\text{ adding (i) and (ii)}
=> 2x = 8 \\
=> x = 4
\end{aligned}
4. Find the value of,
\begin{aligned}
\frac{1}{216^{-\frac{2}{3}}}+\frac{1}{256^{-\frac{3}{4}}}+\frac{1}{32^{-\frac{1}{5}}}
\end{aligned}
- 100
- 101
- 102
- 103
Answer: Option C
5. \begin{aligned}
x = 3 + 2\sqrt{2}, \text{ then the value of }\\
(\sqrt{x} - \frac{1}{\sqrt{x}})
\end{aligned}
- 1
- 2
- 3
- 4
Answer: Option B
Explanation:
Clue:
\begin{aligned}
(\sqrt{x} - \frac{1}{\sqrt{x}})^2 = x + \frac{1}{x} - 2 \
\end{aligned}
Now put the value of x to calculate the answer :)
Thanks ! Your comment will be approved shortly !
- Copyright 2014 - All rights reserved
- Terms Of Use & Privacy Policy
- Contact Us
- Copyright