Question 15 Marks
Rita has bought a carpet of size $4\text{m}\times6\frac{2}{3}\text{m}$ But her room size is $3\frac{1}{3}\text{m}\times5\frac{1}{3}\text{m}$ What fraction of area should be cut off to fit wall to wall carpet into the room?
Answer
View full question & answer→Given, carpet size $=4\text{m}\times6\frac{2}{3}\text{m}=4\times\frac{(6\times3)+2}{3}$
$=4\times\frac{(18+2)}{3}=4\times\frac{20}{3}$
$=\frac{4}{1}\times\frac{20}{3}=\frac{80}{3}=\frac{80}{3}\text{m}^{2}$
$\because$ Room size $=3\frac{1}{3}\text{m}\times5\frac{1}{3}\text{m}$
$=\frac{(3\times3)+1}{3}\times\frac{(5\times3)+1}{3}$
$=\frac{(9+1)}{3}\times\frac{(15+1)}{3}$
$=\frac{10}{3}\times\frac{16}{3}=\frac{160}{9}\text{m}^{2}$
$\therefore$ Difference between the area of carpet and room sizes = size of the carpet - size of the room $=\frac{80}{3}-\frac{160}{9}=\frac{240-160}{9}=\frac{80}{9}\text{m}^{2}$
[$\because LCM$ of $3$ and $9 = 9]$
In fraction, $\frac{\text{Area that will be cut - of}}{\text{Original area}}$
$\frac{\big(\frac{80}{9}\big)}{{\big(\frac{80}{3}\big)}}=\frac{80}{9}\times\frac{3}{80}=\frac{1}{3}$
Hence, $\frac{1}{3}$ of area should be cut - off.
$=4\times\frac{(18+2)}{3}=4\times\frac{20}{3}$
$=\frac{4}{1}\times\frac{20}{3}=\frac{80}{3}=\frac{80}{3}\text{m}^{2}$
$\because$ Room size $=3\frac{1}{3}\text{m}\times5\frac{1}{3}\text{m}$
$=\frac{(3\times3)+1}{3}\times\frac{(5\times3)+1}{3}$
$=\frac{(9+1)}{3}\times\frac{(15+1)}{3}$
$=\frac{10}{3}\times\frac{16}{3}=\frac{160}{9}\text{m}^{2}$
$\therefore$ Difference between the area of carpet and room sizes = size of the carpet - size of the room $=\frac{80}{3}-\frac{160}{9}=\frac{240-160}{9}=\frac{80}{9}\text{m}^{2}$
[$\because LCM$ of $3$ and $9 = 9]$
In fraction, $\frac{\text{Area that will be cut - of}}{\text{Original area}}$
$\frac{\big(\frac{80}{9}\big)}{{\big(\frac{80}{3}\big)}}=\frac{80}{9}\times\frac{3}{80}=\frac{1}{3}$
Hence, $\frac{1}{3}$ of area should be cut - off.













