3600 kg => 100 %
1 kg => 100/3600 %
900 kg => 900*100/3600 % =$${\frac{{\mathtt{900}}{\mathtt{\,\times\,}}{\mathtt{100}}}{{\mathtt{3\,600}}}} = {\mathtt{25}}$$ %
3600 kg => 100 %
1 kg => 100/3600 %
900 kg => 900*100/3600 % =$${\frac{{\mathtt{900}}{\mathtt{\,\times\,}}{\mathtt{100}}}{{\mathtt{3\,600}}}} = {\mathtt{25}}$$ %