## Chapter 8 Comparing Quantities Exercise 8.2

**Question 1: Convert the given fractional numbers to percent.(a) 1/8 **

**Answer:**

1/8 x 100 = 100/8 = 12.5%

**(b) 5/4**

Answer:

Answer:

5/4 x 100 = 500/4 = 125%

**(c) 3/40**

Answer:

Answer:

3/40 x 100 = 300/40 = 7.5%

**(d) 2/7**

Answer:

Answer:

2/7 x 100 = 200/7 = 28 4/7%

**Question 2: Convert the given decimal fraction to percent.**

(a) 0.65

Answer:

(a) 0.65

Answer:

65/100 x 100 = 6500/100 = 65%

**(b) 2.1**

Answer:

Answer:

21/10 x 100 = 2100/10 = 210%

**(c) 0.02**

Answer:

Answer:

2/100 x 100 = 200/100 = 2%

(d) 12.35

Answer:

1235/100 x 100 = 123500/100 = 1235%

**Question 3: Estimate what part of the figures is coloured and hence find the per cent which is coloured.**

(i)

(i)

**Answer:**

The shaded part is 1/4.

1/4 x 100 = 100/4 = 25%.

(ii)**Answer:**

The shaded part is 3/5.

3/5 x 100 = 300/5 = 60%.**(iii)****Answer:**

The shaded part is 3/8.

3/8 x 100 = 300/8 = 37.5%.**Question 4: Find:(a) 15% of 250Answer:**

15/100 x 250 = 3750/100 = 37.5

(b) 1% of 1 hour

Answer:

(b) 1% of 1 hour

Answer:

1/100 x 1 = 1/100 = 0.01 hour

**(c) 20% of ₹ 2500**

Answer:

Answer:

20/100 x 2500 = 50000/100 = ₹500

**(d) 75% of 1 kg**

Answer:

75/100 x 1000 = 75000/100 = 750 grams

Answer:

Question 5: Find the whole quantity if

(a) 5% of it is 600

Answer:

Question 5: Find the whole quantity if

(a) 5% of it is 600

Answer:

= 5% of __ = 600

= 5/100 x x=600 = 1x/20=600

= x = (600 x 20)/1 = 12000

**(b) 12% of it is ₹ 1080.**

Answer:

Answer:

= 12% of __ = ₹ 1080

= 12/100 x x=₹ 1080 = 3x/25=₹1080

= x = (1080 x 25)/3 = 27000/3 = ₹ 9000

**(c) 40% of it is 500 km**

Answer:

= 40% of __ = 500 km

Answer:

= 40/100 x x=500 km = 2x/5= 500 km

= x = (500 x 5)/2 = 2500/2 = 1250 km

**(d) 70% of it is 14 minutes**

Answer:

Answer:

= 70% of __ = 14 minutes

= 70/100 x x=14 minutes = 7x/10= 14 minutes

= x = (14 x 10)/7 = 140/7 = 20 minutes

**(e) 8% of it is 40 liters**

Answer:

Answer:

= 8% of __ = 40 liters

= 8/100 x x=40 liters = 2x/25= 40 liters

= x = (40 x 25)/2 = 1000/2 = 500 liters

Question 6: Convert given percent to decimal fractions and also fractions in simplest forms:

(a) 25%

Answer:

Question 6: Convert given percent to decimal fractions and also fractions in simplest forms:

(a) 25%

Answer:

= 25% = 25/100 = 1/4

**(b) 150%**

Answer:

Answer:

= 150% = 150/100 = 3/2

**(c) 20%**

Answer:

Answer:

= 20% = 20/100 = 1/5

(d) 5%

Answer:

(d) 5%

Answer:

= 5% = 5/100 = 1/20

**Question 7: In a city, 30% are females, 40% are males and remaining are children. What per cent are children?**

Answer:

Answer:

Percentage of female in the city = 30%

Percentage of male in the city = 40%

Percentage of children in the city = ?

= 100% - (30% + 40%)

= 100% - 70%

= 30%

Therefore, the percentage of the children in the city is 30%.

Question 8: Out of 15,000 voters in a constituency, 60% voted. Find the percentage of voters who did not vote. Can you now find how many actually did not vote?

Answer:

Question 8: Out of 15,000 voters in a constituency, 60% voted. Find the percentage of voters who did not vote. Can you now find how many actually did not vote?

Answer:

Total number of voters = 15000

Percentage of voters who voted = 60%

Percentage of voters who didn’t vote = ?

= 100% - 60%

= 40%

Therefore, out of 15000 voters, 40% of the voters didn’t vote.

Number of the voters who didn’t vote = ?

= 40/100 x 15000 600000/100 = 6000

Therefore, 6000 voters didn’t vote.

**Question 9: Meeta saves ₹ 4000 from her salary. If this is 10% of her salary. What is her salary?**

Answer:

Answer:

Amount Meeta saves from her salary = ₹ 400

= 10% of her salary

(Let her salary be x)

= 10% of x = ₹ 400

= 10/100 x x=400

= 1x/10 =400

= x = (400 x 10)/1 = ₹ 4000

Therefore, Meeta’s salary is ₹ 4000.

**Question 10: A local cricket team played 20 matches in one season. It won 25% of them. How many matches did they win?**

Answer:

Answer:

Total matches played = 20

Percentage of matches won = 25%

Therefore, number of matches won = 25% of 20

= 25/100 x 20 = 500/100 = 5

Therefore, they won 5 matches.

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