Answer :

Total is 421, 
United States (104)+ China (88)+ Russia (82)+ Germany (44)+ Japan (3*)
= 104 + 88 + 82 + 44 = 318 (idk wat japan # is)

so because ur photo is cut off u need to do *318 + japan's number* then do 421 minus *that number* that is what great Britain ( x ) is 

so in the end x (great Britain) = 65

very easy
just add up all the meadals

japan is 38

so total=104+88+82+x+44+38=356+x
total of all medals is 421 so to find brittan or x you just subtrac the total from the big total so

356+x=421
subtract 356 from both sides
x=65
brittan won 65 medals