1) I solved 9 coupled non linear differential equation and Mathematica give me the result like this.
[FONT="Courier New"]{{y1[t]->InterpolatingFunction[{{0.001,0.01}},<>][t],
y2[t]->InterpolatingFunction[{{0.001,0.01}},<>][t],
y3[t]->InterpolatingFunction[{{0.001,0.01}},<>][t]...