Ex 2.5 Q2 Fractions and Decimals - NCERT Maths class 7

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Question

Express as rupees using decimals:

i) \(7\) rupees \(7\) paise

ii) \(7\) rupees \(7\) paise

iii) \(7\) rupees \(7\) paise

iv) \(7\) rupees \(7\) paise

v) \(7\) rupees \(7\) paise

 Video Solution
Fractions And Decimals
Ex 2.5 | Question 2

Text Solution

What is known?

Amount in paise.

What is unknown?

Amount in rupees.

Reasoning:

\(1\) paise \(=\) \(\begin{align}\frac{1}{{100}}\end{align}\)rupees

Steps:

i) \(7\) paise

\(100\) paise \(=\) \(1\) rupees

\(1\) paise \(=\) \( \begin{align}\frac{1}{{100}}\end{align}\) rupees

\(7\) paise \(=\) \(7\) \(×\)\(\begin{align}\frac{1}{{100}}\end{align}\)rupees \(= 0.07\) rupees

ii) \(7\) rupees \(7\) paise

\(100\) paise \(=\) \(1\) rupees

\(1\) paise \(=\) \( \begin{align}\frac{1}{{100}}\end{align}\)rupees

\(7\) rupees \(7\) paise \(=\)  \(7\) rupees \(+\) \(7\) paise

\(=\) \(7\) rupees \(+\) \(7\) \(×\)\( \begin{align}\frac{1}{{100}}\end{align}\)rupees 

\(=\) \(7\) rupees \(+\) \(0.07\) rupees

\(=\) \(7.07\) rupees

iii) \(77\) rupees \(77\) paise

\(77\) rupees \(77\) paise \(=\)  \(77\) rupees \(+\) \(77\) paise

\(=\) \(77\) rupees + \(77\) \(×\) \(\begin{align}\frac{1}{{100}}\end{align}\)rupees

\(\because\)\(100\) paise \(=\) \(1\) rupees)

(\(\therefore\) \(1\) paise \(=\) \(\begin{align}\frac{1}{{100}}\end{align}\)rupees)

\(=\) \(77\) rupees \(+\) \(0.77\) rupees

\(=\) \(77.77\) rupees

iv) \(50\) paise

\(\therefore\) \(100\) paise \(=\) \(1\) rupees

\(\therefore\) \(1\) paise \(=\) \(\begin{align}\frac{1}{{100}}\end{align}\) rupees

\(50\) paise \(=\) \(50\) \(×\)\( \begin{align}\frac{1}{{100}}\end{align}\)rupees

=> \(50\) paise \(=\) \(\begin{align}\frac{{50}}{{100}}\end{align}\)rupees

\(50\) paise \(=\) \(0.50\) rupees

v) \(235\) paise

\(\therefore\) \(100\) paise \(=\) \(1\) rupees

\(\therefore\) \(1\) paise \(=\) \(\begin{align}\frac{1}{{100}}\end{align}\) rupees

\(235\) paise \(=\) \(235\) \(×\) \(\begin{align}\frac{1}{{100}}\end{align}\) rupees

\(235\) paise \(=\) \(\begin{align}\frac{{235}}{{100}}\end{align}\)rupees

\(235\)paise \(=\) \(2.35\) rupees