Question

Media aritmetica a 4 nr este1904. Aflati nr stiind ca primul este 60% din al doilea, al doilea este 60% din al treilea si al treilea este 60 % din al patrulea.
Urgent:) ms mult

Answer 1

(a+b+c+d)/4=1904
a=60% b=60/100b=3/5b
b=60% c=60/100c=3/5c
c=60% d=60/100d=3/5d
(3/5b+3/5c+3/5d+d)/4=1904
(3/5*3/5c+3/5*3/5d+3/5d+d)/4=1904
(9/25*3/5d+9/25d+3/5d+d)/4=1904
(272/125d)/4=1904
d=(1904*500)/272
d=3500
c=3/5d=2100
b=3/5c=1260
a=3/5b=759

atat:)

Answer 2

(a+b+c+d)/4=1904
a+b+c+d=1904x4
a+b+c+d=7616
a=bx60% =6b/10
b=cx60%=6c/10  ⇒c=10b/6
c=dx60%=6d/10  ⇒ 10b/6=6d/10 ⇒d=100b/36
6b/10+b+10b/6+100b/36=7616    se aduce la acelasi numitor  care este 180
108b+180b+300b+500b=7616x180
1088b=7x1088x180
b=7x180=1260
a=1260x60%=756
c=1260/60%=2100
d=2100/60%=3500