Question

20. What percent of 392 is 98? 22. 33% of what number is 145? 24, 17 is 40% of what number?

Answer 1

20)

if we take 392 to be the 100%, what is 98 off of it in percentage?

$\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 392&100\\ 98&p \end{array}\implies \cfrac{392}{98}=\cfrac{100}{p}\implies p=\cfrac{98\cdot 100}{392}$

22)

let's say is "x", so if "x" is the 100%, and we know that 145 is the 33%, what the dickens is "x"?

$\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ x&100\\ 145&33 \end{array}\implies \cfrac{x}{145}=\cfrac{100}{33}\implies x=\cfrac{145\cdot 100}{33}$

24)

again, if we take "x" to be the 100%, and we know that 17 is 40%, what is "x"?

$\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ x&100\\ 17&40 \end{array}\implies \cfrac{x}{17}=\cfrac{100}{40}\implies x=\cfrac{17\cdot 100}{40}$