You can
put this solution on YOUR website!% of in crease and % of decrease follows a simple formula

Lets start with problem #3

or

or 60%
Problem #4

or

2/3 = .6 repeating ........
66 2/3%
Now for the first two:
1. What number increased by 30% = 260?
1x + .3x = 260
1.3x = 260
x = 200
2. What is 66 2/3% less than 45? (66 2/3 % ... from prob #4 is 2/3)
1x = 45 - 2/3x
4/3x = 45
x = 33 3/4