Unit:
2: Fraction
and Decimals
Exercise: 2.1 (8)
Question: 1
Solve:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Question: 2
Arrange
the following in descending order:
(i)
(ii)
Solution
(i)
Convert these fractions into like fractions.
Now arrange these fractions in descending order.
Therefore,
(ii)
[Converting into like fractions]
[Arranging in descending order]
Therefore,
Question: 3
In
a “magic square”, the sum of the numbers in each row, in each column and along
the diagonal is the same. Is this a magic square?
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Solution
Sum of first row
Sum of second row
Sum of third row
Sum of first column
Sum of second column
Sum of third column
Sum of first diagonal (left to right)
Sum of second diagonal (left to right)
Since the sum of fractions in each row, in each column and
along the diagonals are same, therefore it is a magic square.
Question: 4
A
rectangular sheet of paper is long and wide. Find its perimeter.
Solution
Given:
The sheet of paper is in rectangular form.
Length of sheet and
Breadth of sheet
Perimeter of rectangle
Thus, the perimeter of the rectangular sheet is
Question: 5
Find
the perimeters of (i) (ii) the rectangle BCDE in this figure. Whose
perimeter is greater?
Solution
(i)
In
The perimeter of
Thus, the perimeter of is .
(ii)
In
Perimeter of
rectangle
Thus, the perimeter of
rectangle is
Comparing the perimeter of
triangle and that of rectangle,
Therefore, the perimeter of triangle is greater than that of rectangle
Question: 6
Salil
wants to put a picture in a frame. The picture is wide.
To
fit in the frame the picture cannot be more than wide. How much should the picture be trimmed?
Solution
Given:
The width of the picture
and the width of picture frame
Therefore, the picture should be trimmed
Thus, the picture should be trimmed by
Question: 7
Ritu
ate part of an apple and the remaining apple was
eaten by her brother Somu. How much part of the apple did Somu eat? Who had the
larger share? By how much?
Solution
The part of an apple eaten by Ritu
The part of an apple eaten by Somu
Comparing the parts of apple eaten by both Ritu and Somu
Larger share will be more by part.
Thus, Ritu’s part is more than Somu’s part.
Question: 8
Michael
finished colouring a picture in hour. Vaibhav finished colouring the same
picture in hour. Who worked longer? By what fraction was it longer?
Solution
Time taken by Michael to colour the picture
Time taken by Vaibhav to colour the picture
Converting both fractions in like fractions,
Here,
Thus, Vaibhav worked longer time.
Vaibhav worked longer time by
Thus, Vaibhav took hour more than Michael.
Exercise: 2.2 (8)
Question: 1
Which
of the drawings (a) to (d) show :
(i)
(a)
(ii)
(b)
(iii) (c)
(iv) (d)
Solution
(i)
– (d) Since
(ii)
– (b) Since
(iii) – (a) Since
(iv) – (c) Since
Question: 2
Some
pictures (a) to (c) are given below. Tell which of them show:
(i)
(a)
(ii)
(b)
(iii)
(c)
Solution
(i)
– (c)
Since
(ii)
– (a)
Since
(iii)
– (b)
Since
Question: 3
Multiply
and reduce to lowest form:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
Question: 4
Shade:
(i)
of the circles in box
(ii)
of the triangles in box
(iii) of the squares in box.
Solution
(i)
of circles
(ii)
of 9 triangles
(iii)
of 15 squares
Question: 5
Find:
a.
of (i) 24 (ii) 46
b.
of
(i) 18 (ii) 27
c.
of
(i) 16 (ii) 36
d.
of
(i) 20 (ii) 35
Solution
a. (i)
(ii)
b.
(i)
(ii)
c.
(i)
(ii)
d.
(i)
(ii)
Question: 6
Multiply
and express as a mixed fraction:
a.
b.
c.
d.
e.
f.
Solution
a.
b.
c.
d.
e.
f.
Question: 7
Find
a.
of (i) (ii)
b.
of (i) (ii)
Solution
a. (i) of
(ii) of
b.
(i) of
(ii) of
Question: 8
Vidya
and Pratap went for a picnic. Their mother gave them a water bag that contained
5 litres of water. Vidya consumed of the water. Pratap consumed the remaining water.
(i)
How much water did Vidya drink?
(ii)
What fraction of the total quantity of water did Pratap drink?
Solution
Given:
Total quantity of water in bottle
(i)
Water consumed by Vidya
Thus, Vidya drank 2 litres water from the
bottle.
(ii)
Water consumed by Pratap
part of bottle
Pratap consumed of litres water litres
Thus, Pratap drank part of the total quantity of water.
Exercise: 2.3 (8)
Question: 1
Find:
(i)
of (a) (b) (c)
(ii)
of (a) (b) (c)
Solution
(i)
(a) of
(b) of
(c) of
(ii)
(a) of
(b) of
(c) of
Question: 2
Multiply
and reduce to lowest form (if possible):
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Question: 3
For
the fractions given below:
a. Multiply and reduce the
product to lowest form (if possible)
b. Tell whether the fraction
obtained is proper or improper.
c. If the fraction obtained is
improper then convert it into a mixed fraction.
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Question: 4
Which
is greater:
(i)
of or
of
(ii)
of or
of
Solution
(i)
Left side expression of
Right side expression of
Since, numerators are same
and denominator of second term is smaller, so it will be greater fraction.
Thus, is greater.
(ii)
of or of
Left side
expression
Right side expression
Clearly,
Thus, is greater.
Question: 5
Saili
plants 4 saplings, in a row, in her garden. The distance between two adjacent
saplings is . Find the distance between
the first and the last sapling.
Solution
The distance between two adjacent saplings
Saili planted saplings in a row, then the gaps between the
first and the fourth sapling
Therefore, The distance between the first and the last
sapling
Thus, the distance between the first and the last sapling is
Question: 6
Lipika
reads a book for hours every day. She reads the entire book in days. How many hours in all were required by
her to read the book?
Solution
Time Lipika devotes every day to read a book hours.
She took days to read a book.
Now, no of hours taken by her to read the entire book
Thus, .5
hours were required by her to read the entire book.
Question: 7
A
car runs using litre of petrol. How much distance will it
cover using litres of petrol.
Solution
In litre of pertrol, car covers the distance
In litres of petrol, car covers the distance of
Thus, the car will cover .
Question: 8
a. (i) Provide the number in the box , such that
(ii) The simplest form of the number obtained in is _______.
b. (i) Provide the number in the box , such that
(ii) The simplest form of the number obtained in is _____.
Solution
a. (i)
(ii) The simplest form of
b.
(i)
(ii) The simplest form of
Exercise: 2.4 (4)
Question: 1
Find:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Question: 2
Find
the reciprocal of each of the following fractions. Classify the reciprocals as
proper fractions, improper fractions and whole numbers.
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Solution
(i)
Reciprocal of Improper fraction
(ii)
Reciprocal of Improper fraction
(iii) Reciprocal
of Proper fraction
(iv) Reciprocal
of Proper fraction
(v)
Reciprocal of Proper fraction
(vi) Reciprocal
of Whole number
(vii) Reciprocal
of Whole number
Question: 3
Find:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Question: 4
Find:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
Exercise: 2.5 (9)
Question: 1
Which
is greater?
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Question: 2
Express
as rupees using decimals:
(i)
7 paise
(ii)
7 rupees 7 paise
(iii) 77
rupees 77 paise
(iv) 50 paise
(v)
235 paise.
Solution
(i)
(ii)
(iii)
(iv)
(v)
Question: 3
(i)
Express in metre and kilometre.
(ii)
Express in cm, m and km.
Solution
(i)
Express in metre and kilometre.
Now,
(ii)
Express in cm, m and km.
Now,
Again,
Question: 4
Express
in kg:
(i)
(ii)
(iii)
(iv)
Solution
We know that,
(i)
(ii)
(iii)
(iv)
Question: 5
Write
the following decimal numbers in the expanded form:
(i)
(ii)
(iii)
(iv)
Solution
(i)
(ii)
(iii)
(iv)
Question: 6
Write
the place value of in the following decimal numbers:
(i)
(ii)
(iii)
(iv)
(v)
Solution
(i)
Place value of in
(ii)
Place value of in
(iii) Place value of in
(iv) Place value of in
(v)
Place value of in
Question: 7
Dinesh
went from place A to place B and from there to place C. A is from B and B is from C. Ayub went from place A to place D and
from there to place C. D is from A and C is from D. Who travelled more and by how much?
Solution
Distance travelled by Dinesh when he went from place A
to place and from place B to
Total distance covered by Dinesh
Total distance covered by Ayub
On comparing the total distance of Ayub
and Dinesh,
Therefore, Ayub covered more distance by
Question: 8
Shyama
bought apples and mangoes. Sarala bought oranges and bananas. Who bought more fruits?
Solution
Total weight of fruits bought by Shyama
Total weight of fruits bought by Sarala
On comparing the quantity of fruits,
Therefore, Sarala bought more fruits.
Question: 9
How
much less is than ?
Solution
We have to find the difference between and .
Difference
Therefore, is less than .
Exercise: 2.6 (5)
Question: 1
Find:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Question: 2
Find
the area of rectangle whose length is and breadth is .
Solution
Given:
Length of rectangle and Breadth of rectangle
Area of rectangle Length Breadth
Thus, the area of rectangle is .
Question: 3
Find:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
(xi)
(xii)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
(xi)
(xii)
Question: 4
A
two-wheeler covers a distance of in one litre of petrol. How much distance will
it cover in of petrol?
Solution
In one litre, a two-wheeler
covers a distance
In litres, a two-wheeler covers a distance
Thus, distance will be covered by it in litres
of petrol.
Question: 5
Find:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
Exercise: 2.7 (6)
Question: 1
Find:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
Question: 2
Find:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Question: 3
Find:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Question: 4
Find:
(i)
(ii)
(iii)
(iv)
(v)
Solution
(i)
(ii)
(iii)
(iv)
(v)
Question: 5
Find:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
Solution
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
Question: 6
A
vehicle covers a distance of in of petrol. How much distance will it cover in
one litre of petrol?
Solution
In litres of petrol, distance covered by the
vehicle
In litre of petrol, distance covered by the
vehicle
Thus, it covered distance in one litre of petrol.