Question

ajutati_ma dau coroana

Answer 1

Fie x=drumul total
in prima zi a parcurs a=3/10*x. a doua zi a parcus b=4/7 din ce a ramas (deci din x-3/10*x=7/10*x), y=4/7*7/10*x=2/5*x.
In primele 2 zile a parcurs (3/10+2/5)*x=7/10*x
in ultima zi a parcurs 3/10*x=450, deci x=1500km.