What is the meaning of 3 upon 8?

Dear Student,

3 upon 8 means 3/8 and,

3/8 is three parts out of Eight ,
also expressed as 0.375 or 37.5%.
For example:-
a class of 24 children has 3/8 part are boys

Maens there 24 *3/8 =9 are boys



Regards