Rawls' philosophy that inequalities are justified if they benefit the position of the least-advantaged person is known as the

Rawls' philosophy that inequalities are justified if they benefit the position of the least-advantaged person is known as the: difference principle.
For example, let's say that there is a running competition between grown man and young boy. But, the grown man has to run carrying a 50kgs of weight on his shoulder.
In this case, even though there is inequality in the race, it's justified because it benefit the least-advantage person(the young boy)