Răspuns :
15 robinete ----------------------600 l apa
20 robinete ----------------------x l apa
15 * x=20*600
15 x=12000
x=800 l apa
20 robinete ----------------------x l apa
15 * x=20*600
15 x=12000
x=800 l apa
15 r.............................600 l apa
20 r.................................x l apa
x = 20·600:15 = 12000:15 = 800 l apa
20 r.................................x l apa
x = 20·600:15 = 12000:15 = 800 l apa