in a class of 60 junior and senior students, 21 are girls and 34 are juniors and 20 are senior boys. How many juniors are girls?
Tb=Ts[60]−Tg[21]
Tb=39
Jb=Tb[39]−Sb[20]
Jb=19
Jg=Tj[34]−Jb[19]
Jg=15
Answer:
15