Question 251896
It is difficult to give simple yes or no answers to this. The answers depend on what is being increased or decreased. For example, 150% increases are probably possible most of the time. But a speed of a particle moving at 80% of the speed of light cannot be increased 150% because that would make it exceed the speed of light.<br>
150% decreases can make sense if negative value make sense. For example, someone's net worth could decrease 150% (to where they owe more than the value of what they possess.) But on the other hand populations cannot decrease by 150% because a negative number for population is meaningless.<br>
So the "short" answers:
150% increases are possible unless there is some fixed upper limit that cannot be exceeded.
150% decreases are possible if negative values have meaning.