# Class 7 Maths | Chapter 8 Comparing Quantities | Extra Questions For Practice

Answer the following:

1. Find the ratio of each of the following in simplest form:

a) Rs 5 to 50 paise

b) 18 m to 36 cm

2. Check whether the following ratios are equivalent:

a) 2:3 and 12:18

b) 4:7 and 9:12

3. Find the unknown y so that both ratios are equivalent:

a) y:8 : : 3:12

b) 24: 36:: y: 9

4. If the cost of one dozen pens are 60. Find the cost of 5 pens?

5. Divide 240 rupees between Anu and Manu in the ratio 3:5?

6. Convert the following percents into ratios and write in simplest form:

a) 15%

b) 65%

7. Convert the following ratios to percents:

a) 3:4

b) 5:8

8.30% of a number is 75. Find the number?

9. Convert the following percents to decimals:

a) 37%

b) 8%

10. Convert the following decimals to percents:

a) 0.56

b) 0.7

**ANSWERS:**

1. a) Rs 5 to 50 paise

We know that 100 paise = 1 rupee

Therefore, Rs 5 = 500 paise

Ratio = 500:50 = 10:1 (Divide by 50)

b) 18 m to 36 cm

We know that 100 cm = 1 m

Therefore, 18 m = 1800 cm.

Ratio = 1800:36 = 50:1 (Divide by 36)

2. a) 2:3 and 12:18

Here, 2 x 18 = 36(Extreme terms)

2 x 12 = 36 (Middle terms)

So these ratios are equivalent.

b) 4:7 and 9:12

Here, 4 x 12 = 48

7 x 9 = 63

So these ratios are not equivalent.

3. a) y:8::3:12

Since the ratios are equivalent, y x 12 = 8 x 3

y x 12 = 24

y = 24/12 = 2

b) 24:36:: y:9

Since the ratios are equivalent, 24 x 9 = 36 x y

216 = 36 x y

Y = 216/36 = 6

4. Cost of 12 pens = 60 rupees

Cost of one pen = 60/12 = 5 rupees

Cost of 5 pens = 5 x 5 = 25 rupees

5. Part of Anu = 3/8

Part of Manu = 4/8

We need to divide 240 rupees in the ratio 3:5.

Share of Anu = 240 x 3/8 = 90 rupees

Share of Manu = 240 x 5/8 = 150 rupees

6. a) 15% = 15/100 = 3/20= 3:20

b) 65% = 65/100 = 13/20 = 13:20

7. a) 3:4

¾ x 100% = 75%

b) 5:8

5/8 x 100= 62.5%

8. Let the number be y.

30% of y = 75

30/100 x y =75

30 y = 7500

Y = 7500/30 = 250

9. a) 37%

37/100 = 0.37

b) 8%

8/100 = 0.08

10. a) 0.56 =0.56 x 100% = 56%

b) 0.7 = 0.7 x 100% = 70%