x-lungimea drumului
2/3 din x= 2/3 * x= 2x/3 -in prima parte
x-2x/3= (3x-2x)/3= x/3 -restul
2/5 din x/3 =2/5 * x/3= 2x/15 -in a2a parte
x/3 -2x/15= (5x-2x)/15= 3x/15 -noul rest
1/5 din 3x/15= 1/5 * 3x/15= 1/5 * x/5= x/25 -in a3a parte
3x/15-x/25= (15x-3x)/75= 12x/75 -noul nou rest
12x/75=60
x=75*60/12
x=75*5
x=375
b)2x/3=2*375/3= 2*125=250 -in prima parte
2x/15= 2*375/15= 2*25=50 -in a2a parte
375/25=15 -in a3a parte