Well, if the product has two decimal places and it is known that one factor has none, then the other factor must have two decimal places. Where would those two decimal places in the product come from otherwise?
30 is the old value and 55 is the new value. In this case we have a positive change (increase) of 83.33333333 percent because the new value is greater than the old value. Using this tool you can find the percent increase for any value.