Question

If 21 is added in a number then a result becomes 137X1/2%of no. find the number.
step by step exlanation
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Answer 1

Step-by-step explanation:

Let no. be = x

x + 21 = 137 * (0.5)x

x + 21 = 68.5x

67.5x = 21

x = 21/67.5 = 0.311(approx.)

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Answer 2

Answer:

We can find that number using the given data in the question. For that we should change percentage into fraction. That number is : $56$

Step-by-step explanation:

From the given question, $21$ is added in a number then a result becomes

$137\frac{1}{2}$% of a number.

Here the number will be consider as $x$.

$21$ is added in a number can be written as ⇒ $x+21$

Result is   $137\frac{1}{2}$ % of number can be written as ⇒ $137\frac{1}{2}$ % $x$

It should be written as,

                     $x+21=137\frac{1}{2}$ % $x$ ---------------(1)

Here we should convert this mixed fraction into the improper fraction.

For that, procedure of mixed fraction to improper fractions:

• Rule 1:Multiply the whole number by the denominator

• Rule 2:Add the answer from rule 1 to the numerator

• Rule 3:Write answer from rule 2 over the denominator

$137\frac{1}{2}$ ⇒ mixed fraction. Here whole number: $137$, numerator: $1$, denominator: $2$

Rule 1 for the mixed fraction:  $137*2=274$

Rule 2 for the mixed fraction: $274+1=275$

Rule 3 for the mixed fraction:   $137\frac{1}{2}=\frac{275}{2}$              

Now the equation (1) should be written as,

                          $x+21=\frac{275}{2}$ % $x$ ------------------(2)

Now $\frac{275}{2}$ % percentage into fraction. For that percentage value should be divided by $100$.

That is,                $\frac{275}{2}$ % $=\frac{275/2}{100}$

                           $\frac{275}{2}$ % $=\frac{275}{200}$

Equation (2) should be written as,

                         $x+21=\frac{275}{200}x$   ⇒ Divided by $5$

                         $x+21=\frac{55}{40}x$    ⇒ Divided by $5$

                         $x+21=\frac{11}{8}x$

                     $8(x+21)=11x$

                      $8x+168=11x$

                               $168=11x-8x$

                               $168=3x$

                                $3x=168$

                                  $x=\frac{168}{3}$

                                  $x=56$

Final Answer: Number is $56$