20%+25%+160=100%
45%+160=100%
160=100%-45%
160=55%
55%..........................................160m.
45%...........................................x m.
x=45x160:55=130,90
100%=130,90+160=290,90
20% = 58,181 m ( 290,90x20:100)
25% =72,5=725 m (290x25:100)
R: lungimea totala a primelor 2 bucati este : 130,90 m.