Question

22 is 20% of what number?

A) 11

B) 44

C) 110

D) 440

Answer 1

C) 110

Explanation:

`\bold{Method\ 1}\\\\\begin{array}{ccc}22&-&20\%\\x&-&100\%\end{array}\qquad\text{cross multiply}\\\\20x=(22)(100)\\20x=2200\qquad\text{divide both sides by 20}\\x=110`

`\bold{Method\ 2}\\\\\begin{array}{cccc}22&-&20\%&\text{multiply both sides by 5}\\5\cdot22&-&5\cdot20\%\\110&-&100\%\end{array}`

`\bold{Method\ 3}\\\\p\%=(p)/(100)\to 20\%=(20)/(100)=0.2\\\\n-number\\\\20\%\ of\ n\ is\ 22\to0.2x=22\qquad\text{divide both sides by 0.2}\\\\x=(22)/(0.2)\\\\x=(220)/(2)\\\\x=110`

Answer 2

C) 110.

Explanation:

To find it you must multiply in number by 5.

22*5=110.

To prove it you must divide it into 5, since 20 is the fifth part of 110.

110/5=22.