NCERT Class 7 Mathematics

COMPARING QUANTITIES 159 Colour Number Fraction Denominator Hundred In Percentage of Beads Red 8 8 20 8 20 100 100 40 100 ×= 40% ...

160 MATHEMATICS Mala has a collection of bangles. She has 20 gold bangles and 10 silver bangles. What is the percentage of bang ...

COMPARING QUANTITIES 161 From these examples, we find that the percentages related to proper fractions are less than 100 whereas ...

162 MATHEMATICS table, observe and complete it: Per cent 1% 10% 25% 50% 90% 125% 250% Fraction 1 100 10 100 1 10 = Decimal 0. 01 ...

COMPARING QUANTITIES 163 8 .3.5 Fun with Estimation Percentages help us to estimate the parts of an area. EXAMPLE 11 What per ce ...

164 MATHEMATICS TRY THESE Arun does it like this Out of 100, 25 like playing football So out of 40, number of children who like ...

COMPARING QUANTITIES 165 Convert the given decimal fractions to per cents. (a) 0.65 (b) 2.1 (c) 0.02 (d) 12.35 Estimate what pa ...

166 MATHEMATICS EXAMPLE 15 If Rs 250 is to be divided amongst Ravi, Raju and Roy, so that Ravi gets two parts, Raju three parts ...

COMPARING QUANTITIES 167 Amount of change = decrease in the number of illiterate persons = 150 – 100 = 50 lakhs Therefore, the p ...

168 MATHEMATICS Thus, the profit is Rs 8 and profit Per cent is 111 9 . Neha does it this way Shekhar does it this way Profit pe ...

COMPARING QUANTITIES 169 EXAMPLE 19 Selling price of a toy car is Rs 540. If the profit made by shop- keeper is 20%, what is the ...

170 MATHEMATICS SOLUTIONThe sum borrowed = Rs 5,000, Rate of interest = 15% per year. This means if Rs 100 is borrowed, she has ...

COMPARING QUANTITIES 171 EXAMPLE 21 If Manohar pays an interest of Rs 750 for 2 years on a sum of Rs 4,500, find the rate of int ...

172 MATHEMATICS Amina buys a book for Rs 275 and sells it at a loss of 15%. How much does she sell it for? Find the amount to b ...

9.1 INTRODUCTION You began your study of numbers by counting objects around you. The numbers used for this purpose were called c ...

174 MATHEMATICS 9.3 WHAT ARE RATIONAL NUMBERS? The word ‘rational’ arises from the term ‘ratio’. You know that a ratio like 3:2 ...

RATIONAL NUMBERS 175 Equivalent rational numbers A rational number can be written with different numerators and denominators. Fo ...

176 MATHEMATICS
Is^8 3 a negative rational number? We know that 8 3 = 8× 1 3× 1= 8 3 , and 8 3 is a negative rational number. ...

RATIONAL NUMBERS 177 In the same way, the rational numbers 1 2 and 1 2 would be at equal distance from 0. We know how to mark th ...

178 MATHEMATICS A rational number is said to be in the standard form if its denominator is a positive integer and the numerator ...