Page 18 - SM inner class 7.cdr

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10. Find the equiv a lent frac tion of with.
48
(a) numerator 9 (b) denominator 4
11. Write shaded portion as fraction. Arrange them in descending order using correct sign ' ',' ',' '< = >
be tween the frac tions.

3 3
12. Rafiq ex er cised for of an hour, while Rohit ex er cised for of hour. Who ex er cised for a lon ger time?
6 4

Multiplication of Fractions 3. Simplify the resulting fraction if not in
1. Multiplying a Fraction by a Whole low est terms.
5
Num ber æ 10 ö æ ö
Ex am ple 9. = Solve ç ÷ ´ ç ÷.
7
If you need to multiply a fraction by a whole è 2 ø è ø
number, you should convert the whole number So lu tion: By di viding; mul ti pli ca tion of
to an improper fraction where that number is nu mer a tors by mul ti pli ca tion of de nom i na tors and
the numerator and 1 is the denominator. we get;
2 (10 ´ ) [Multiplication of Numerators]
5
Ex am ple 8. (a) ´ 5. =
3 (2 ´ ) [Multiplication of Denominator]
7
5
So lu tion : Con vert 5 into : Solve the brackets and we get;
1 50
2 5 =
´ 14
3 1
Divide both numerator and denominator by 2
Now just go ahead as normal.
to convert fraction into lowest term and we get;
Multiply tops and bottoms: 25 4
= = 3
2 ® 5 10 1 7 7
´ = = 3
3 ® 1 3 3 20 4
Ex am ple 10. Mul ti ply and
The fraction is already as simple as it can be. 3 10

Ex am ple 8 (b) : So lu tion : The pro ceed is as
4 Divide; multiplication of numerators by
´ 7.
5 multiplication of denominators and we get;
4
7 (20 ´ )
So lu tion : Since; 7 = =
1 (3 ´10 )
4 7 28 3
´ = = 5 Solve the brackets and we get;
5 1 5 5 80
=
2. Multiplying Two Fractions 30
To multiply two fractions : Divide both numerator and denominator by 10
1. Mul ti ply the nu mer a tors of the frac tions to convert fraction into lowest term and we get;
to get the new nu mer a tor. 8 2
= = 2
2. Mul ti ply the de nom i na tor of the frac tions 3 3
to get the new de nom i na tor.

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Mathematics In Focus - 7