Răspuns:
a+b+c+d =360 grade
a:1/8 =b:1/10 =c:1/20 =d:1/40 =k
a=k/8
b=k/10
c=k/20
d=k/40
k/8+k/10+k/20+k/40 =360 numitor 40
5k+4k+2k+k =14400
12k=14400
k=1200
a=1200/8 =150 grade
b=1200/10 =120 ''
c=1200/20 =60 ''
d=1200/40 =30 ''
Explicație pas cu pas: