This year ben is 12 years old and his mom is 48 years old.what percent of his mom's age is Ben age?

Both answers are the same but why did you multiply by 12/12 Titanium.  That was a bit pointless  

Just do 12/48, and multiply the decimal by 100 to get the percent.

12/48 divide by 12/12 equals 1/4 times by 100

equals=25

which equals 25%