Thursday, 5 April 2012

CBSE Class 6th ( VI) Mathematics Chapter 7. Fractions: Exercise 7.4

Let us Remember..

  1. Fractions with same denominators are called like fractions. For example, 1/15, 2/15, 3/15, 8/15 are all like fractions.
  2. Fractions with different denominators are called unlike fractions. 11/27 and 9/28 are unlike fractions
  3. For given any two fraction the fraction with the same denominator, the fraction with the greater numerator is greater. For example Between 4/5 and 3/5, 4/5 is greater. Between 11/20 and 13/20, 13/20 is greater and so on.
  4. when we compare two unlike fractions, we first get their equivalent fractions with a denominator which is a common multiple of the denominators of both the fractions
1. Write shaded portion as fraction. Arrange them in ascending and descending order using correct sign '<', '=', '>' between the fractions:





2486
(c) Show


and
on the number line. Put appropriate signs between the fractions given.
6666
5231685


,
0,

,

6666666
Answer:
 
1346

<
<
<
8888

3468

<
<
<
9999

(c)
 

5231685


,
0,

,

6666666

2. Compare the fractions and put an appropriate sign.
35
a.

66
11
b.

74
45
c.

55
33
d.

57
Answer:
35
a.

66
11
b.

74
45
c.

55
33
d.

57
3. Make five more such pairs and put appropriate signs. Answer:
53
1.
>
88
155
2.
>
136
59
3.
<
1112
54
4.
>
65
33
5.
=
33
4. Look at the figures and write '<' or '>', '=' between the given pairs of fractions.





















 
11
a.

63
32
b.

46
22
c.

34
63
d.

63
55
e.

65


Answer:
11
a.

63
32
b.

46
22
c.

34
63
d.

63
55
e.

65
5. How quickly can you do this? Fill appropriate sign. ( '<', '=', '>')
11
a.

25
23
b.

46
32
c.

53
32
d.

48
36
e.

55
73
f.

99
12
g.

48
64
h.

105
37
i.

48
64
j.

105
515
k.

721
Answer:
11
a.

25
23
b.

46
32
c.

53
32
d.

48
36
e.

55
73
f.

99
12
g.

48
64
h.

105
37
i.

48
64
j.

105
515
k.

721
6. The following fractions represent just three different numbers. Separate them into three groups of equivalent fractions, by changing each one to its simplest form.
   
Answer:
21
a.
=
126
31
b.
=
155
44
c.
=
5025
164
d.
=
10025
101
e.
=
606
1516
f.
=
755
121
g.
=
605
161
h.
=
966
124
i.
=
7525
121
j.
=
726
31
k.
=
286
44
l.
=
2525
11111
a.
  e.
  h.
j.
  k.
66666
111
b.
  f.
  g.
555
4444
c.
  d.
  i.
 l.
25252525
7. Find answers to the following. Write and indicate how you solved them.
54
a.Is
equal to
?
95
55
b.Is
equal to
?
169
416
c.Is
equal to
?
520
14
d.Is
equal to
?
1530
Answer: a.
5254362536
No;
=
,
=
and

9455454545
b.
9815808180
No;
=
,
=
and

1614491441 44144
c.
416
Yes;
=
520
d.
12482 8
No;
=
,
=
and

1530306030 60
8. Ila read 25 pages of a book containing 100 pages. Lalita read
2

of the same book. Who read less ?
5 
Answer:
The fraction of pages Ila read-25/100 = 1/4
The fraction of pages Ila read= 2/5
Comparing both the fractions= 1x5/4x5=5/20, 2x4/5x4=8/20
Clearly 5/20 is less than 8/20i.e. 5/20 < 8/20
There for Illa reads less
33
9. Rafiq exercised for
of an hour, while Rohit exercised for
64
Who exercised for a longer time?
Answer:
3
The fraction of an hour, Rafiq exercised for =
6
3
The fraction of an hour, Rohit exercised for =
4
Comparing both the fractions
3x263x39

=
,
=
6x2124x312
96
As
>
There for Rohit excercised for longer time
1212

10. In a class A of 25 students, 20 passed in first class; in another class B of 30 students, 24 passed in first class. In which class was a greater fraction of students getting first class? Answer;
In a class A of 25 students, 20 passed in first class
There for the fraction of students of class A, passed in first class = 20/25
In a class B of 30 students, 24 passed in first class
There for the fraction of students of class B, passed in first class = 24/30
The fractions are unlike. We should first get their equivalent fractions with a denominator which is a common multiple of 25 and 30.Clearly common denominator is 150 which is in fact LCM of 25 and 30. After having equivalent fraction for both, we can easily compare the fractions of students getting First Class in both the classes.
  
20×6120424×51204

=
=
,
=
=
25×6150530×51505
44
As
=
55
4
∴ Same fraction i.e.  
of students got first class in both classes.
5

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