Question

Dintr-un vas se scoate prima oara 1 supra 5 din continut, apoi 1 supra 4 din rest, ina 1 supra 3 din noul rest,iar dupa ce se mai scoate 1 supra 2 din ceea ce a ramas, in vas mai raman 20 litri.Cati litri erau in vas,la inceput?

Answer 1

x - litri vas

I.
1/5*x=x/5

x-x/5=4x/5 rest

II.
1/4*4x/5=x/5

4x/5-x/5=3x/5 noul rest

III.
1/3*3x/5=x/5

3x/5-x/5=2x/5 noul noul rest

IV.
1/2*2x/5=x/5

2x/5-x/5=20
x/5=20
x=5*20
x=100 litri

Answer 2

x litri vas l    /5*x=x/5
x-x/5=4x/5 rest
ll 1/4*4x/5=x/5
4x/5-x/ 5 3/x/5 noul rest
lll1/3*3x/5=/5
3x/5-x/5=2x/5 noul rest
lV1/2*2x/5=20
x/5=20
x=5+20
x=100litri