First write the dimension of each quantity and then relate them.Force \\\\([F]=[MLT^{-2}]=100N\\\\)............(i)length\\\\([L]=[L]=10m\\\\)................(ii)Time \\\\([t]=[T]=100s\\\\)..............(iii)Substituting values of L and T from Eqs.(ii) and (iii) in Eq.(i) , we get\\\\(M\ imes 10\ imes (100) ^{-2}=100\\\\)\\\\(\\Rightarrow=\\dfrac{M \ imes 10}{100 \ imes 100=100}\\\\)\\\\(\\Rightarrow=M=100 \ imes 1000 kg=10^5kg\\\\)