a+b+c+d= 375
a-20/100*a = b-40/100*b= c-25/100*c= d-50/100*d
a- a/5 = b-2b/5= c-c/4= d-d/2
4a/5 = 3b/5=3c/4= d/2
⇒
16a=12b=15c=10d
⇒
b=16a/12=4a/3
c= 16a/15
d=16a/10=8a/5
a+4a/3+16a/15+8a/5=375
15a+20a+16a+24a=5625
75a=5625
a=75
b=4*75/3=100
c=16*75/15=80
d=8*75/5=120
75+100+80+120=375