Explicație pas cu pas:
3 c ........5 p ..........2300 g/×4
4c...........2p............1200 g/x3
12 c ......20 p ...... 9200g
12c .........6p.........3600 g
___________________
///...........14 p ......5600g
1p = 5600 :14
1p = 400g
3c + 5x400=2300
3c + 2000= 2300
3c = 2300 - 2000
3c = 300
c = 300 :3
c = 100 g
