Question

1.Un automobilist a parcurs un drum in patru zile .In prima zi a parcurs 1/5 din intregul drum si inca 30km ,a doua zi 2/5 din rest si inca 30km,a treia zi 1/2 din noul rest si inca 10km,iar a patra zi ultimii 50km.Care este lungimea intregului drum parcurs in cele patru zile?

Answer 1

x=lungime drum
x/5+30=ziua 1
x-(x/5+30)=4x/5-30=rest
(4x/5-30)×2/5+30=8x/25+18= ziua 2
4x/5-30-(8x/25+18)=12x/25-48=rest
(12x/25-48)×1/2+10=12x/50-24+10=6x/25-14=ziua 3
x/5+30+8x/25+18+6x/25-14+50=x
x/5+14x/25+84=x
5x+14x+2100+=25x
6x=2100
x=350 km