Calculate the percentage of population in your city

By M. Venkat
Director
MVK Publications
Dilsukhnagar
7671002120

This article is in continuation to the last article focusing on the percentage topic. Here are some practice questions along with solutions on the percentage topic that will help you in your preparation for the State government recruitment jobs.

1. The population of a town increases by 10% every year. If the present population is 20000, in the next year it will be?

a) 20000 b) 22000 c) 21500 d) 22500
Ans: b

Solution: A = P(1 R/100)n
= 20000 ( 1 10/100)1

= 20000 × 110/100 = 22000

2. The number of people in a town increased by 4% at the beginning of each year. If the present population of the town is 50000, then the population after two years will be?

a) 54080 b) 54000 c) 53900 d) 53900
Ans: a

Solution: A = P(1 R/100)n

= 50000(1 4/100)2
= 50000 × (104/100)2
= 50000 × 26/25 × 26/25 = 54080

3. The population of a town increases at the rate of 10% every year. The present population is 1000. In how many years will the population become 1331?

a) 2 b) 2 c) 3 d) 3
Ans: c

Solution: A = P(1 R/100)n

= 1331/1000 = (1 10/100)n
= (11/10)3 = (11/10)n

=>; n = 3

4. A town’s population is growing at the rate of 5% per year. If the present population of the town is 1,85,220, then what was the population of the town one year ago?

a) 1,76,000 b) 1,76,300 c) 1,76,350 d) 1,76,400
Ans: d

Solution: A = P(1 R/100)n

A = 1, 85, 220(1 5/100) -1

= 1, 85, 220 × 100/105
= 1,76,400

5. The population of a town increases by 5% every year. If the present population is 9261, the population 3 years ago was?

a) 5700 b) 7500 c) 8000 d) 6000
Ans: c

Solution: A = P( 1 R/100)n

= 9261 × (1 5/100)-3

= 9261 × ( 1 105/100) -3

= 9261 × (21/20)-3

= 9261 × 20/21 × 20/21 × 20/21 = 8000

6. The population of a town 2 years ago was 62,500. Due to migration to big cities, it decreases every year at the rate of 4%. The present population of the town is?

a) 56,750 b) 56,700 c) 57,600 d) 57,650
Ans: c

Solution: 62500 (1 – 4/100)2

= 62500 × (96/100)

= 62500 × 24/25 × 24/25 = 57,600

7. If the population of a village increased from 1,75,000 to 2,62,500 in 5 years, then find the average percentage increase in the population per year.

a) 10% b) 12% c) 13% d) 15%
Ans: a

Solution: Population of village = 1,75,000

After 5 years, population of village = 2,62,500

Increase in population = 2,62,500 – 1,75,000

= 87,500

Average increase in population per year

= 87, 500/5 = 17, 500

Percentage increase = 17, 500/ 1, 75, 000 × 100 = 10%

8. In a town, the population was 8000. In one year, male population increased by 10% and female population increased by 8% but the total population increased by 9%. The number of males in the town is?

a) 4500 b) 4000 c) 3750 d) 5250
Ans: b

Solution: Male Female

10% 8%

9%

1% 1%

Number of males = 1/2 × 8000 = 4000

9. The population of a town is 10,000. If the male population increases by 5% and the female population by 10% the population will become 10,800. How much of the town’s present population is female?

a) 5000 b) 6000 c) 5750 d) 6500
Ans: b

Solution: (10, 800 – 10,000)/ 10, 000 × 100% = 800/ 10,000 × 100%
= 8%
Male Female
5% 10%

8%

2% 3% 3/5 × 10000 = 6000

To be continued…