Question

Please can anyone answer this percentage question cor grade 7

Answer 1

well, we know it was 480, then we reduce it by 50.

a)

if we take 480 to be the 100%, what's 50 off of it in percentage?

`\begin{array}{ccll} amount&\%\\ \cline{1-2} 480 & 100\\ 50& x \end{array} \implies \cfrac{480}{50}~~=~~\cfrac{100}{x} \\\\\\ \cfrac{ 48 }{ 5 } ~~=~~ \cfrac{ 100 }{ x }\implies 48x=500\implies x=\cfrac{500}{48}\implies x=\cfrac{125}{12}\implies \boxed{x\approx 10.4}`

now, the TV is only 480 - 50 = 430, then it gets reduced another 50.

if we take 430 to be the 100%, what's 50 off of it in percentage?

`\begin{array}{ccll} amount&\%\\ \cline{1-2} 430 & 100\\ 50& y \end{array} \implies \cfrac{430}{50}~~=~~\cfrac{100}{y} \\\\\\ \cfrac{ 43 }{ 5 } ~~=~~ \cfrac{ 100 }{ y }\implies 43y=500\implies y=\cfrac{500}{43}\implies \boxed{y\approx 11.6}`

b)

hmmm the absolute change of the reductions? that sounds like 480 - 50 - 50 = 380.

c)

well, the overall percentage hmmm well, that's the $100 reduction total.

if we take $480 as the 100%, what's $100 off of it in percentage?

`\begin{array}{ccll} amount&\%\\ \cline{1-2} 480 & 100\\ 100& z \end{array} \implies \cfrac{480}{100}~~=~~\cfrac{100}{z} \\\\\\ \cfrac{ 24 }{ 5 } ~~=~~ \cfrac{ 100 }{ z }\implies 24z=500\implies z=\cfrac{500}{24}\implies z=\cfrac{125}{6}\implies \boxed{z\approx 20.8}`