# Worksheet on Concept of Proportion

Practice the questions given in the worksheet on concept of proportion.

We know, four numbers p, q, r and s are in proportion i.e., p : q = r : s if and only if ps = qr.

Conversely, if ps ≠ qr, then p, q, r and s are not in proportion.

1. In each of the following questions, check whether the given ratios form a proportion or not:

(i) 8 : 16 and 12 : 15

(ii) 16 : 28 and 24 : 42

(iii) 12 ÷ 3 and 8 ÷ 2

(iv) 25 : 40 and 20 : 32

(v) 15/18 and 10/12

(vi) 7/8 and 14 : 16

2. Find the value of x if:

(i) x : 3 = 15 : 9

(ii) 4 : x = 12 : 45

(iii) 13 : 11 = x : 88

(iv) 1.7 : 5.1 = 1.9 : x

(v) $$\frac{1}{13}$$ : x = ½ : $$\frac{1}{5}$$

3. Which of the following are in proportion?

(i) 5, 7, 25, 35

(ii) 9, 6, 15, 10

(iii) 15, 20, 21, 12

(iv) 11, 7, 55, 35

(v) 9, 13, 72, 105

(vi) 7, 42, 5, 30

4. Find the third proportional to:

(i) 27 and 9

(ii) 2 m 40 cm and 40 cm

(iii) 1.8 and 0.6

(iv) 1/7 and 3/14

(v) 1.6 and 0.8

5. Check whether the numbers 4, 12, 36, are in proportion.

6. (i) If a : b = 1.5 : 3.5 and b : c = 5 : 6, find a : c.

(ii) If 1¼ : 2$$\frac{1}{3}$$ = p : q and q : r = 4½ : 5¼; find p : r.

Answers for the worksheet on concept of proportion are given below to check the exact answers of the above questions using proportion.

1. (i) No

(ii) Yes

(iii) Yes

(iv) Yes

(v) Yes

(vi) Yes

2. (i) 5

(ii) 15

(iii) 104

(iv) 5.7

(v) 2/65

3. (i), (ii), (iv), (vi)

4. (i) 3

(ii) 6 2/3 cm

(iii) 0.2

(iv) 9/28

(v) 0.4

5. yes

6. (i) 5 : 14

(ii) 45 : 98