Question Number 59095 by necx1 last updated on 04/May/19
$${An}\:{building}\:{student}\:{makes}\:{a}\:{floor} \\ $$$${plan}\:{of}\:{a}\:{building}\:{on}\:{a}\:{scale}\:{of}\:\mathrm{1}:\mathrm{75}.{At} \\ $$$${what}\:\%\:{change}\:{will}\:{he}\:{need}\:{to}\:{convert} \\ $$$${it}\:{to}\:{a}\:{scale}\:{of}\:\mathrm{1}:\mathrm{250}? \\ $$
Answered by MJS last updated on 04/May/19
$$\mathrm{as}\:\mathrm{before} \\ $$$$\mathrm{length}\:\frac{\mathrm{75}}{\mathrm{250}}=\frac{\mathrm{3}}{\mathrm{10}}\:\Rightarrow\:−\mathrm{70\%} \\ $$$$\mathrm{area}\:\frac{\mathrm{75}^{\mathrm{2}} }{\mathrm{250}^{\mathrm{2}} }=\frac{\mathrm{9}}{\mathrm{100}}\:\Rightarrow\:−\mathrm{91\%} \\ $$