Tag: decimal fraction

Questions Related to decimal fraction

$0.04\times 0.0162$ is equal to:

  1. $6.48\times { 10 }^{ -3 }$

  2. $6.48\times { 10 }^{ -4 }$

  3. $6.48\times { 10 }^{ -5 }$

  4. $6.48\times { 10 }^{ -6 }$


Correct Option: B
Explanation:

$4\times 162=648$. Sum of decimal places $= 6$.
So, $0.04\times 0.0162=0.000648=6.48\times { 10 }^{ -4 }$

What is $27\times 1.\overline {2} \times 5.526\overline {2} \times 0.\overline {6}$ equal to?

  1. $121.5\overline {7}$

  2. $121.\overline {75}$

  3. $121.7\overline {5}$

  4. None of the above


Correct Option: A
Explanation:

It can be solved as $27\times 1.\overline {2} \times 5.526\overline {2} \times 0.\overline {6}$
$= 27\times \left (1 + \dfrac {2}{9}\right )\times \dfrac {6}{9} \times (5.526\overline {2})$
$= 27\times \dfrac {11}{9}\times \dfrac {2}{3}\times (5.526\overline {2})$
$= 22\times (5.526\overline {2})$
$= 22\times (5.5 + 0.026\overline {2})$
$= 121 + (22\times 0.026\overline {2})$
$= 121 + 0.\overline {57}$
$= 121.\overline {57}$

The value of $\dfrac { 489.1375\times 0.0483\times 1.956 }{ 0.0873\times 92.581\times 99.749 } $ is closest to:

  1. $0.006$

  2. $0.06$

  3. $0.6$

  4. $6$


Correct Option: B
Explanation:

$\dfrac { 489.1375\times 0.0483\times 1.956 }{ 0.0873\times 92.581\times 99.749 } \approx \dfrac { 489\times 0.05\times 2 }{ 0.09\times 93\times 100 } $
$=\dfrac { 489 }{ 9\times 93\times 10 } $
$=\dfrac { 163 }{ 279 } \times \dfrac { 1 }{ 10 } $
$=\dfrac { 0.58 }{ 10 } $
$=0.058\approx 0.06$.

Multiply: $24\times 12.23$

  1. $123.36$

  2. $236.56$

  3. $293.52$

  4. $2935.2$


Correct Option: C
Explanation:
Multiplying and dividing by $100$ we get
$24\times 12.23 = (24\times1223)\div100$
                    $=293.52$

Multiply:
$1563.58\times25$

  1. $39,380.5$

  2. $390.895$

  3. $3,908.95$

  4. $39,089.5$


Correct Option: D
Explanation:
Multiplying and dividing by $100$ we get
$1563.58\times 25 = (156358\times25)\div100$
                    $=39089.5$

Multiply:
$123\times24.53$

  1. $3017.19$

  2. $30171.9$

  3. $307.719$

  4. $30.719$


Correct Option: A
Explanation:
Multiplying and dividing by $100$ we get
$123\times 24.53 = (123\times2453)\div100$
                    $=3017.19$

Find the value of $x$
$83^{27.3}\div 83^{1.4}\times 83^{46.8}=83^{31.9+x}$

  1. $64.1$

  2. $41.9$

  3. $40.8$

  4. $39.1$

  5. None of these


Correct Option: C
Explanation:

Consider L.H.S
$83^{27.3}\div 83^{1.4}\times 83^{46.8}$
$=(83)^{27.3-1.4+46.8}=(83)^{72.7}$
$\Rightarrow 31.9+x=72.7$
$\Rightarrow x=72.7-31.9=40.8$.

Solve the following:
$19.7\times 4$


$78.8$

  1. True

  2. False


Correct Option: A
Explanation:

Step 1 : $197 x 4 = 788$

Step 2 : Total number after decimal $= 1$

So, $19.7 \times  4 = 78.8$

Solve the following:
$0.05\times 7$ = $0.35$

  1. True

  2. False


Correct Option: A
Explanation:

Step 1 : $5 \times  7 = 35$

Step 2 : Total number after decimal $= 2$
So, $0.05 \times  7 = 0.35$

Solve the following:
$4.3\times 3.4$


Ans: $14.62$

  1. True

  2. False


Correct Option: A
Explanation:

Given, $4.3 \times  3.4$

Step I: $43 \times 34 = 1462$
Step II: Total number after decimal $= 2$
So, $4.3 \times 3.4 = 14.62$
Hence , given statement is true