The word per cent means per 100. to calculate a percent of a total divide the number you were given by the total and then multiply by

The first thing you must do to solve the problem is the following rule of three:the total > 100
 the number you were given > x
 Clearing x we have:
 x = ((the number you were given) / (the total)) * (100)
 Therefore, you must multiply by 100.
 
 divide the number you were given by the total and then multiply by 100

The equation is  125+22m=b