|
Percentages
February 10, 2004
The difference between the value of a number increased by 12.5% and the value of the original number decreased by 25% is 30. What is the original number?
| (A) | 60 |
| (B) | 80 |
| (C) | 40 |
| (D) | 120 |
| (E) | 160 |
Correct Answer (B) Choice (80)
Solution:
Let the original number be x.
Let A be the value obtained when x is increased by 12.5%.
Therefore, A = x + 12.5% of x
Let B be the value obtained when x is decreased by 25%.
Therefore, B = x - 25% of x
The question states that A - B = 30
i.e., x + 12.5% of x - (x - 25% of x) = 30
x + 12.5% of x - x + 25% of x = 30
37.5% of x = 30
x =  = 80
| 
