Question

The cost of three pens and four pencils is ₹177.If a pen costs ₹17 more than a pencil,find the cost of a pen and pencil​

Answer 1

Given: The cost of three pens and four pencils is ₹177. & A pen costs ₹17 more than a pencil.

Need to find: Dimensions of rectangular park?

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❍ Let's consider cost of pencil as x & cost of pencil as x + 17.

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As we know that,

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$\begin{gathered}\star\:{\underline{\boxed{\frak{Cost \: of \: 3 \: pens \: and \: 4 \: pencils = 177}}}}\\\\\\ \bf{\dag}\:{\underline{\frak{Putting\:given\:values,}}}\\\\\\ :\implies\sf 3(x+ 17) + 4x= 177\\\\\\ :\implies\sf 3x + 51 + 4x = 177 \\\\\\ :\implies\sf 7x + 51 = 177 \\\\\\ :\implies\sf 7x = 177 - 51 \\\\\\ :\implies\sf 7x = 126 \\\\\\:\implies\sf x = \dfrac{126}{7}\\\\\\ :\implies{\underline{\boxed{\frak{\purple{x = 18}}}}}\:\bigstar\\\\\end{gathered}$

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Therefore,

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Cost of pencil, x = 18 Rupees.

Cost of pen, 17 + x = 17 + 18 = 35 rupees.

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$\therefore\:{\underline{\sf{Hence,\:Cost\:of\:pen\:and\:pencil\:is\:\bf{35}\: \sf{and}\: \bf{18}\: \sf{respectively}.}}}$

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★ More to know:

★ Proportional method: In this method, To find the multiple unit, When two ratios are equal, We can multiply the product of means with the product of extremes, To find the unknown value in those ratios.

★ Unitary method : In this method Firstly we will find the value of single unit, Then multiply it with the required number to find the required unit.