Assume that the original value is x.
Part (a):
First an 80% increase. This means that the value became:
x + 80%x = x + 0.8x = 1.8x
Then 40% decrease. This means that the value became:
1.8x - 40%x = 1.8x - 0.4x = 1.4x
Therefore:
Value is greater than original.
Part (b):
First an 50% decrease. This means that the value became:
x - 50%x = x + 0.5x = 0.5x
Then 100% increase. This means that the value became:
0.5x + 100%x = 0.5x + 1x = 1.5x
Therefore:
Value is greater than original.
Part (c):
First an 20% increase. This means that the value became:
x + 20%x = x + 0.2x = 1.2x
Then 25% decrease. This means that the value became:
1.2x - 25%x = 1.2x - 0.25x = 0.95x
Therefore:
Value is less than original.
Part (d):
First an 33.3% decrease. This means that the value became:
x - 33.3%x = x - 0.333x = 0.667x
Then 50% increase. This means that the value became:
0.667x + 50%x = 0.667x + 0.5x = 1.167x
Therefore:
Value is greater than original.
Part (e):
First an $25 increase. This means that the value became:
x + $25
Then $30 decrease. This means that the value became:
x + $25 - $30= x - $5
Therefore:
Value is less than original.
Hope this helps :)
