Page 91 - ICSE Math 5

Exercise 6.4

1. Find the reciprocal of the following numbers.
3 2
(a) (b) (c) 14 (d) 1
11 5

2. Divide the following.
1 2 1
(a) 7 ÷ (b) 22 ÷ (c) 32 ÷ 2
3 5 3
6 6 1
(d) ÷ 3 (e) 3 ÷ 13 (f) 4 ÷ 2
7 11 4
3. Divide the following fractions.

2 8 7 1 1 20 5 4
(a) ÷ (b) ÷ (c) 3 ÷ (d) 4 ÷ 2
7 21 9 3 8 18 9 27
4. Fill in the blanks.
5 5 8
(a) ÷ = ________ (b) ÷ 1 = ________
7 7 11
 (c) 0 ÷ 13 = ________ (d) 9 ÷ 0 = ________
15 20
Word Problems on Addition and Subtraction of Fractions
3 2 1
Example 31: A bus covers 55 km in the first hour, 58 km in the second hour and 78 km in
4 5 2
the third hour. Find the total distance covered by the bus in these three hours.
3 223
Solution: Distance covered by the bus in the first hour = 55 km = km
4 4
2 292
Distance covered by the bus in the second hour = 58 km = km
5 5
1 157
Distance covered by the bus in the third hour = 78 km = km
2 2
Total distance covered by the bus in these three hours
223 292 157
= + + km (L.C.M. of 4, 5 and 2 is 20.)
4 5 2
223 × 5 292 × 4 157 × 10
= + + km
4 × 5 5 × 4 2 × 10

1115 1168 1570
= + + km
20 20 20
1115 + 1168 + 1570 3853 13
= km = km = 192 km.
20 20 20
13
So, the total distance covered by the bus in these three hours is 192 km.
20

81