Question

clasa a 3-a 
intr-un bazin curge apa prin doua robinete:
-prin primul cate 198 l/min 
-prin al doilea cu 90 l mai putin 
cate litri de apa sunt in bazin dupa 3 minute?
(2 moduri +exercitiu)

Answer 1

Primul mod:

Primul robinet:

198l........1min

xl..........3min

x=3*198=594

Al doilea robinet:

198-90=108l/min

108l....1min

yl....3min

y=3*108=324l

In total: 594+324=918

Exercitiul: (3*198)+[(198-90)*3]=594+(108*3)=594+324=918

Al doilea mod:

Prin al doilea robinet curge: 198-90=108

In total: (198+108)*3=306*3=918

Exercitiul: [198+(198-90)]*3=(198+108)*3=306*3=918