Question

4. 30 is what percent of 120?

Answer 1

25%

Explanation:

Divide 30 and 120 then multiply by 100.

Answer 2

If is 4.3

`\large\boxed{4.3\ \text{is}\ 3(7)/(12)\%\approx3.58\%\ \text{of 120}}`

If is 30

`\large\boxed{30\ \text{is}\ 25\%\ \text{of 120}}`

Explanation:

`\bold{METHOD\ 1:}\\\\\begin{array}{ccc}120&-&100\%\\4.3&-&x\%\end{array}\qquad\text{cross multiply}\\\\\\120x=(4.3)(100)\\\\120x=430\qquad\text{divide both sides by 120}\\\\x=(430)/(120)\\\\x=(43)/(12)\\\\x=3(7)/(12)\to x\approx3.58`

`\bold{METHOD\ 2:}\\\\\text{We calculate what fraction of 120 is 4.3}\\\\(4.3)/(120)=(4.3\cdot10)/(120\cdot10)=(43)/(1200)\\\\\text{Convert to the percent:}\\\\(43)/(1200)=(43)/(1200)\cdot100\%=(43)/(12)\%=3(7)/(12)\%`

If is 30:

`\bold{METHOD\ 1:}\\\\\begin{array}{ccc}120&-&100\%\\30&-&x\%\end{array}\qquad\text{cross multiply}\\\\\\120x=(30)(100)\\\\120x=3000\qquad\text{divide both sides by 120}\\\\x=(3000)/(120)\\\\x=25`

`\bold{METHOD\ 2:}\\\\\text{We calculate what fraction of 120 is 30}\\\\(30)/(120)=(1)/(4)\\\\\text{Convert to the percent:}\\\\(1)/(4)=(1)/(4)\cdot100\%=25\%`