Question

Un automobil a parcurs distanta de 160 km in 3 ore.In prima ora a parcurs 30 procente din toata distanta,in a doua ora a parcurs 28 procente din rest.Ce distanta a parcurs automobilul in a treia ora?

Answer 1

$\rm a+b+c=160 \\ \\ a= \frac{3\not0\cdot16\not0}{1\not0\not0}=\bold{48~km} \\ \\ Rest:160-48=112~km \\ \\ b= \frac{28*112}{100}=\bold{31,36~km} \\ \\ 48+31,36+c=160 \\ \\ c+79,36=160|-79,36 \\ \\ \bold{c=80,64~km}$