Tag: maths

Questions Related to maths

Simplify : $\displaystyle \left [ 3\frac{1}{4}\div \left { 1\frac{1}{4}-\frac{1}{2}\left ( 2\frac{1}{2}-\frac{1}{4}-\frac{1}{6} \right ) \right } \right ]\div \left ( \frac{1}{2}of4\frac{1}{3} \right )$

  1. 18

  2. 36

  3. 39

  4. 78


Correct Option: B
Explanation:

Given exp.
$\displaystyle =\left [ \frac{13}{4}\div \left { \frac{5}{4}-\frac{1}{2}\left ( \frac{5}{2}-\frac{3\, \, \,2}{2} \right ) \right } \right ]\div \left ( \frac{1}{2}of\frac{13}{3} \right )$
$\displaystyle =\left [ \frac{13}{4}\div \left { \frac{5}{4}-\frac{1}{2}\left ( \frac{5}{2}-\frac{1}{12} \right ) \right } \right ]\div \frac{13}{6} $
$=\displaystyle \left [ \frac{13}{4}\div \left { \frac{5}{4}-\frac{1}{2}\times \frac{30-1}{12} \right } \right ]\div \frac{13}{6}$
$\displaystyle =\left [ \frac{13}{4}\div \left { \frac{5}{4}-\frac{29}{24} \right } \right ]\div \frac{13}{6}$
$\displaystyle =\left [ \frac{13}{4}\div \frac{30-29}{24} \right ]\div \frac{13}{6}$
$\displaystyle =\left ( \frac{13}{4} \div \frac{1}{24}\right )\div \frac{13}{4}=\frac{13}{4}\times 24\times \frac{6}{13}=36$

If $2805\,\div\, 2.55\, =\, 1100\,, then\, 280.5\,\div\,25.5\, =\,$ .............

  1. 1.1

  2. 1.01

  3. 0.11

  4. 11


Correct Option: D
Explanation:

$\displaystyle\frac{280.5}{25.5}\,=\, \frac{280.5}{25.5}\,\times\, \frac{10}{10}\,\times\, \frac{10}{10}$

$=\,\displaystyle\frac{2805}{2.55}\,\times\,\frac{1}{100}$

$=\,\displaystyle\frac{1100}{100}\,=\, 11$

$143.6\, \div\, 2000\, =\,..........$

  1. 0.1718

  2. 7.18

  3. 0.718

  4. 0.0718


Correct Option: D
Explanation:

$143.6\div 200=71.8\div100=0.0718$

 Hence the answer is option is D

15 of $\displaystyle \frac{1}{5}$ is

  1. $\displaystyle \frac{1}{75}$

  2. $\displaystyle \frac{151}{5}$

  3. 3

  4. -3


Correct Option: C
Explanation:

15 of $\displaystyle \frac{1}{5}\, =\, 15\, \times\, \displaystyle \frac{1}{5}\, =\, 3$

If $\sqrt{5}=2.236$ and $\sqrt{10}=3.162$, the value of $\displaystyle\frac{\sqrt{10}-\sqrt{5}}{\sqrt{2}}$ on simplifying is

  1. 0.455

  2. 0.855

  3. 0.655

  4. 0.755


Correct Option: C
Explanation:

values of $\sqrt { 5 } $ and $\sqrt { 10 } $ are given.

as per problem,
$\frac { \sqrt { 10 } -\sqrt { 5 }  }{ \sqrt { 2 }  } $
$\frac { 3.162-2.236 }{ 1.414 } $(value of $\sqrt { 2 } $ is1.414)
$\frac { 0.926 }{ 1.414 } $
$0.655$

The value of $\displaystyle\frac{1}{\sqrt{3}+\sqrt{2}-1}$ on simplifying upto 3 decimal places, given that $\sqrt{2}=1.4142$ and $\sqrt{6}=2.4495$ is

  1. 0.166

  2. 0.366

  3. 0.466

  4. 0.566


Correct Option: C
Explanation:

$\frac { 1 }{ \sqrt { 3 } +\sqrt { 2 } -1 } $
$=\frac { \sqrt { 3 } -\left( \sqrt { 2 } -1 \right)  }{ \left( \sqrt { 3 } +\left( \sqrt { 2 } -1 \right)  \right) \left( \sqrt { 3 } -\left( \sqrt { 2 } -1 \right)  \right)  } Multiplying\sqrt { 3 } -\left( \sqrt { 2 } -1 \right) \quad with\quad numerator\quad and\quad denominator\quad $
$=\frac { \sqrt { 3 } -\left( \sqrt { 2 } -1 \right)  }{ 3-{ \left( \sqrt { 2 } -1 \right)  }^{ 2 } } $
 $=\frac { \sqrt { 3 } -\left( \sqrt { 2 } -1 \right)  }{ 3-{ \left( 2+1-2\sqrt { 2 }  \right)  } } $
 $=\frac { \sqrt { 3\quad  } -\sqrt { 2 } +1 }{ 2\sqrt { 2 }  } $
$=\frac { 1.732-1.4142+1 }{ 2.8284 } =0.466$
                                               $(\sqrt { 3 } =\frac { \sqrt { 6 }  }{ \sqrt { 2 }  } =\frac { 2.4495 }{ 1.4142 } =1.732)$

Place value chart is extended on .............. side to provide place for fractions

  1. right

  2. left

  3. no

  4. None of these


Correct Option: A
Explanation:

That is the role of the decimal point. The decimal point separates the place values that are whole values on the left from the place values that are fractional parts on the right.

So option A is the correct answer.

If $\displaystyle 2805\div 2.55=1100$ then $\displaystyle 280.5\div 25.5=$ _______

  1. 1.1

  2. 1.01

  3. 0.11

  4. 11


Correct Option: D
Explanation:

$\displaystyle \frac{280.5}{25.5}=\frac{280.5}{25.5}\times \frac{10}{10}\times \frac{10}{10}$

$\displaystyle =\frac{2805}{2.55}\times \frac{1}{100}$

$\displaystyle =\frac{1100}{100}=11$

The fraction $\displaystyle \frac{9}{4}$ can be written as

  1. $\displaystyle \dfrac{\dfrac{9}{2}}{\dfrac{4}{2}}$

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

  3. $\displaystyle \dfrac{\dfrac{9}{5}}{\dfrac{4}{5}}$

  4. $\displaystyle \dfrac{\dfrac{7}{6}}{\dfrac{9}{4}}$


Correct Option: A,B,C
Explanation:
$ \dfrac{\dfrac{9}{2}}{\dfrac{4}{2}} = \dfrac{9}{2} \div \dfrac 42 =\dfrac 92 \times \dfrac 24  = \dfrac 94$

$ \dfrac{\dfrac{9}{4}}{1} = \dfrac{9}{4} \div 1 = \dfrac 92 \times 1 = \dfrac 94$

$ \dfrac{\dfrac{9}{5}}{\dfrac{4}{5}} = \dfrac{9}{5} \div \dfrac 45 =\dfrac 95 \times \dfrac 45  = \dfrac 94$

So, options $A, B$ and $C$ are correct.

Which of the following is complex fraction?

  1. $\dfrac{6\dfrac{1}{3}}{9}$

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

  3. $\dfrac{5}{9}$

  4. $\dfrac{8}{9}$


Correct Option: A
Explanation:

$\dfrac{6\dfrac{1}{3}}{9}$ is complex fraction.


So, option A is correct.