Question

Selling price of a toy car is rs 540. If the profit made by the shopkeeper is 20%, what is the cost of price of the toy​

Answer 1

$\large\mathbb{\bold{GIVEN\::}}$

• $\sf{S.P\:=\:Rs\:540}$
• $\sf{Profit\:Percentage\:=\:20\:\%}$

${ }$

$\large\mathbb{\bold{FIND\::}}$

• $\sf{C.P\:=\:?}$

${ }$

$\large\mathbb{\bold{SOLUTION\::}}$

$\bf{\bold{Now,}}$

$\:\:\:\:\:\:\:\:\:{\sf{⊛\:Profit\:=\:S.P.\:-\:C.P}}$

$\:\:\:\:\:\:\:\:\:{\sf{⊛\:Profit\:=\:540\:-\:C.P}}$

${ }$

$\bf{\bold{Also,}}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{Profit\:Percentage\:=\:20\:\%}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{\frac{Profit}{C.P.}}\:༝\:{100\:\%}{\:=\:20\:\%}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{\frac{540\:-\:C.P}{C.P.}}\:=\:{\frac{20\:\%}{100\:\%}}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{\frac{540\:-\:C.P}{C.P.}}\:=\:{\frac{20}{100}}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{\frac{540\:-\:C.P}{C.P.}}\:=\:{\frac{2}{10}}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{\frac{540\:-\:C.P}{C.P.}}\:=\:{\frac{1}{5}}$

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• $\sf{\bold{Cross\:Multiplying\:-}}$

${ }$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{5\:༝\:(540\:-\:CP)\:=\:1\:༝\:C.P}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{2700\:-\:5\:C.P\:=\:C.P}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{2700\:=\:6\:C.P}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{6\:C.P\:=\:2700}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{C.P\:=\:{\frac{2700}{6}}}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{C.P\:=\:{\frac{900}{2}}}$

$\:\:\:\:\:\:\::\:\Longrightarrow\sf{C.P\:=\:Rs.\:450}$

${ }$

${\:\:\:\:\:\:\:∴\:}\:\sf{\underline{So,\:the\:cost\:price\:is\:{\bold{Rs\:450.}}}}$