x-lungimea santului
1/4 din x= 1/4* x= x/4-in 1a zi
x-x/4= (4x-x)/4= 3x/4-restul
3/6 din 3x/4= 3/6 *3x/4= 3/2 * x/4= 3x/8-a 2a zi
3x/4- 3x/8= (6x-3x)/8= 3x/8-noul rest
2/5 din 3x/8= 2/5 * 3x/8= 1/5 *3x/4= 3x/20-a 3a zi
3x/20=24
x=20*24/3= 20*8=160m
160/4=40m-in 1a zi
3*160/8= 3*20=60m-in a2a zi
3*160/20= 3*8=24m-in a3a zi