It is more likely that the boys' bikes are taller than the crate such that their forces are not parallel to the ground. Apply one vector towards the right with 100 N of force at 19o and another vector towards the left with 80 N of force at 167o. Now can you tell whether the box will move towards the left or the right? You can use the SHOW RESULTANT button to find out.
When the forces are not oriented along the same direction how can you tell what the resultant force will be? For the second case above, with how much force will the crate move to the right? How much force will be causing it to move upwards? You can use the SHOW COMPONENTS button if you need help.