Page 207 - Ganit Kaushal

Ex 5. Find answers to the following. Write and indicate how you solved them.
5 4 9 5
(a) Is equal to ? (b) Is equal to ?
9 5 16 9
5 4
Sol. (a) If = , then by the cross product condition, we must get 5 × 5 = 9 × 4. But 5 × 5 ≠ 9 × 4 as
9 5
5 × 5 = 25 and 9 × 4 = 36.
∴ 5 ↑ 4
9 5
(b) We can solve it by the condition of cross products as done in part (i), but for a change, let us do it
by converting them into like fractions as follows:
LCM (16, 9) = 16 × 9 = 144 ( 16 and 9 are co-prime)
×
×
9 99 81 5 516 80
Making the denominators equal, we get: = = and = =
×
16 16 9 144 9 916 144
×
80 81
↑
144 144
9 5
∴ We conclude that ↑ .
16 9
Exercise 7.3

1. Compare the fractions and put the appropriate sign in the boxes.
4 5 3 3
(a) (b)
5 5 5 7
2. Fill in the correct number in the box, if 5 = 20 .
8
3. The following fractions represent just three fractions. Write those three fractions in ascending order.
Also, separate them into three groups of equivalent fractions.
2 3 8 16
(a) (b) (c) (d)
12 15 50 100

(e) 10 (f) 15 (g) 12 (h) 16
60 75 60 96

(i) 12 (j) 12 (k) 3 (l) 4
75 72 18 25
4. Arrange the following fractions in the order as asked:
3 5 34 12 3 5 7 3
(a) ,, , in ascending order. (b) , , , in descending order.
7 9 63 21 8 12 10 20
5. Arrange the following fractions in ascending order.
27 27 27 27 27 11 11 11 11 11
(a) , , , , (b) , , , ,
47 50 100 1000 85 8 25 11 18 10
6. Find answers to the following. Write and indicate how you solved them.
4 16 1 4
(a) Is equal to ? (b) Is equal to ?
5 20 15 30
7. Jeevika takes 10 minutes to take a complete round of the park and her friend Namit takes 13 minutes
4
3
to do the same. Who takes less time? (NCERT)

Fractions 205