Question

Dau coroana daca raspundeti la 4,5,6

Answer 1

4.
x+y+z=42
x/7=y/2 =>x=7y/2
3y=4z =>z=3y/4
7y/2 + y + 3y/4=42
14y+4y+3y=168
21y=168 =>y=8
x=28
z=6

5.
(b+c+a)/3=48 =>b+c+a=144
b/2=c/7=a/9=k
b=2k
c=7k
a=9k
2k+7k+9k=144
18k=144 =>k=8
=>b=16 (biciclist)
=>c=56 (camion)
=>a=72 (autoturism)

6.
12 muncitori __________ 15 zile
10 muncitori __________ x zile 
Este o relatie de invers proportionalitate, adica mai putini muncitori vor lucra mai multe zile.
x=(12·15)/10=18 zile