Find the impulse exerted on the wedge by the ground during impact

[baldbrain]

Homework Statement

This is a lengthy question with many sub-parts but I have a doubt about just one of them.
A ball of mass 1 kg falling vertically downwards with a velocity of 2 m/s strikes a wedge of mass 2 kg kept on a smooth horizontal surface. The given figure shows the motion of the ball during impact. Find the impulse on the wedge from the ground during impact.

Relevant Equations

None

Now, the net vertical impulse on the wedge should be zero. It's quite obvious from the figure that the ground will also exert an impulse of $J cos 30°$ on the wedge. But they've given the answer as $J sin 30°$.
They're wrong, right?

 

[haruspex]

But they've given the answer as $J sin 30°$.
They're wrong, right?

Yes, it’s the cos, but everything in the image you posted looks right. Where do they say it is sin?

 

[baldbrain]

Yes, it’s the cos, but everything in the image you posted looks right. Where do they say it is sin?

At the end of the problem (not in this image). As I said, it has many sub-parts.
Thanks for the clarification.