For #s 4-7
#4) is Increase 35 by 40%
35 * 1.4 = 49
#5)Increase 125 by 8%
125 * 0.08 = 10
#6) Decrease 8 by 75%
8 * 0.75 = 6
#7) Decrease 135 by 22%
135 * 0.22 = 29.7
ARE THESE CORRECT YOU HAD TO FIND THE NEW AMOUNT.
Are you looking for the total amount with the increase or merely the amount of increase?
If the former, method for #4 is correct.
If the latter, the other three answers are using the correct method.