Question

What percent of 70 is 20?

Answer 1

Hint: To find what percent of 70 is 20, we will assume this percentage to be x. Then, we have to write the given condition as $x\%\text{ of }70=20$ . Then, we have to write this form mathematically by changing ‘of’ to multiplication sign(x). Then, we have to convert x% into its number form by dividing x by 100. Then, we have to simplify and find the value of x.

Complete step by step solution:
We have to find what percentage of 70 is 20. Let us assume this percentage to be x. Then we can write the given condition as
$x\%\text{ of }70=20$
Now, let us write the above form mathematically.
$\Rightarrow x\%\times 70=20$
Now, we have to convert x% into its number form. For this, we have to divide x by 100.
$\Rightarrow \dfrac{x}{100}\times 70=20$
Let us cancel a zero from 100 and 70.
$\Rightarrow \dfrac{x}{10\require{cancel}\cancel{0}}\times 7\require{cancel}\cancel{0}=20$
We can write the result of the above simplification as
$\Rightarrow \dfrac{x}{10}\times 7=20$
Now, let us take 7 to the RHS.
$\Rightarrow \dfrac{x}{10}=\dfrac{20}{7}$
Now, we have to take 10 to the RHS.
$\Rightarrow x=\dfrac{20\times 10}{7}$
Let us simplify the numerator of the RHS.
$\Rightarrow x=\dfrac{200}{7}$
Now, we have to convert $\dfrac{200}{7}$ into decimals.
$\Rightarrow x=\dfrac{200}{7}=28.571$
Therefore 28.571% of 70 is 20.

Note: Students must always consider the unknown value as a variable and make an equation using the given conditions and solve for the variable. They must know that in percentage, ‘of’ means multiply. They must know to convert a percentage into its number and a number into its percentage form. To convert a number into its percentage, we have to multiply the number 100 times.