1-3/5=5/5-3/5=2/5 (2/5 din nr. painilor raman dua prima zi)
2/5×7/8=14/40=7/20 (7/20 din nr. painilor s-au vandut a doua zi)
1-3/5-7/20=20/20-12/20-7/20=1/20 (1/20 reprezinta cele 5 paini ramase)
5×20=100 (paini in total)
100×3/5=60 (paini vandute in prima zi)
100×7/20=35 ( paini vandute a doua zi)