Răspuns :
140=l+ll+lll
140=3/7din 140+3/5din(140-3/7din140)+lll
140=3·20+3/5·80+lll
140=60+48+lll
140=108+lll
lll=140-108=32
140=3/7din 140+3/5din(140-3/7din140)+lll
140=3·20+3/5·80+lll
140=60+48+lll
140=108+lll
lll=140-108=32