Ex 2.1 Q6 Fractions and Decimals Solution -NCERT Maths Class 7

Salil wants to put a picture in a frame. The picture is \(\begin{align}7\frac{3}{5}{\rm{cm}}\end{align}\)wide. To fit in the frame the picture cannot be more than \(\begin{align}7\frac{3}{{10}}{\rm{cm}}\end{align}\) wide. How much the picture should be trimmed?

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What is Known?

Width of the picture and frame.

What is unknown?

The frame width is smaller than that the width of the picture. How much the picture should be trimmed so that it fits into the frame.

Reasoning:

Since width of the picture is more, it should be trimmed to make its width equal to the width of the frame. How much picture should be trimmed can be obtained by subtracting width of the frame from the width of the picture.

Steps:

The width of the picture

\(\begin{align} = 7\frac{3}{5}{\rm{cm}} = \frac{{38}}{5}{\rm{cm}}\end{align}\)

Width of the picture frame

 \( \begin{align}=7\frac{3}{{10}}{\rm{cm}}=\frac{{73}}{{10}}{\rm{cm}}\end{align} \) 

Therefore,

The picture should be trimmed 

\[\begin{align} &{ = 7\frac{3}{5}{\rm{cm}} - 7\frac{3}{{10}}{\rm{cm}}}\\ {}&{ = \frac{{38}}{5}{\rm{cm}} - \frac{{73}}{{10}}{\rm{cm}}}\\ {}&{ = \left( {\frac{{76 - 73}}{{10}}} \right){\rm{cm}}}\\&= {\frac{3}{{10}}{\rm{cm}}} \end{align}\]

Thus, the picture should be trimmed \(\begin{align}\frac{3}{{10}} \,\rm{cm}\end{align}\)  to fit in the picture.