Introduction : Percentage

Concept of Percentage:
By a certain percent, we mean that many hundredths.
Thus, x percent means x hundredths, written as x%.

SAMPLE PROBLEMS

1 In a certain school, 20% of students are below 8 years of age. The number of students above 8 years of age is  2/3 of the number of students of 8 years of age which is 48. What is the total number of students in the school?

A. 72
B. 80
C. 120
D. 150
E. 100

2 The population of a town increased from 1,75,000 to 2,62,500 in a decade. The average percent increase of population per year is:

A. 4.37%
B. 5%
C. 6%
D. 8.75%

3 A student multiplied a number by 3/5 instead of 5/3, What is the percentage error in the calculation ?

A. 54%
B. 64%
C. 74%
D. 84%

4 The value of a machine depreciates at the rate of 10% every year. It was purchased 3 years ago. If its present value is Rs. 8748, its purchase price was :

A. 10000
B. 12000
C. 14000
D. 16000

5 If the numerator of a fraction is increased by 150% and the denominator of the fraction is increased by 350%, the resultant fraction is 25/51. What is the original fraction ?

A. 31/25
B. 15/17
C. 14/25
D. 11/16