Răspuns :
a+b+c=288
a |....|
b |....|....|
c |....|....|....|....|....|....| } 288
288:9=32 ( a )
32×2=64 ( b )
64×3=192 ( c )
probă: 32+64+192=288
notam nr a,b,c
a+b+c=288
b=2a
c=3b=3*2a=6a
inlocuim tot in suma in functie de a
a+2a+6a=288
9a=288
a=32
deci b=64
si c= 192