
$N_1 = 120 \cos \theta$
$f_1 = 0.25(120 \cos \theta) = 30 \cos \theta$
$N_2 = N_1 + 200 \cos \theta$
$N_2 = 120 \cos \theta + 200 \cos \theta$
$N_2 = 320 \cos \theta$
$f_2 = 0.25(320 \cos \theta) = 80 \cos \theta$
$f_1 + f_2 = 200 \sin \theta$
$30 \cos \theta + 80 \cos \theta = 200 \sin \theta$
$110 \cos \theta = 200 \sin \theta$
$\dfrac{100}{200} = \dfrac{\sin \theta}{\cos \theta}$
$\tan \theta = \dfrac{11}{20}$
$\theta = 28.81^\circ$ answer