FRACTIONS AND DECIMALS 39
The value of
1
3
×
1
2
can be found in a similar way. Divide the whole into two equal
parts and then divide one of these parts in three equal parts. Take one of these parts. This
will represent^1
3 ×
1
2 i.e.,
1
6
.
Therefore
1
3
×
1
2
1
6
11
32
as discussed earlier.
Hence
1
2
×
1
3
1
3
×
1
2
1
6
Find
1
3
×
1
4
and
1
4
×
1
3
;
1
2
×
1
5
and
1
5
×
1
2
and check whether you get
1
3 ×
1
4 =
1
4 ×
1
3 ;
1
2 ×
1
5 =
1
5 ×
1
2
Fill in these boxes:
(i)
1
2 ×
1
7 =
11
27
= (ii)
1
5 ×
1
7 = =
(iii)
1
7 ×
1
2 = = (iv)
1
7 ×
1
5 = =
Example 6 Sushant reads
1
3 part of a book in 1 hour. How much part of the book
will he read in 21
5
hours?
SOLUTION The part of the book read by Sushant in 1 hour =
1
3
.
So, the part of the book read by him in
21
5
hours =
21
5
×
1
3
11
5
×
1
3
11 1
53
=
11
15
Let us now find
1
2
×
5
3
. We know that
5
3
=
1
3
× 5.
So,
1
2 ×
5
3 =
1
2 ×
1
3 × 5 =
1
6
5 5
6
TRY THESE