The treasure is a
Hints/tips: You will want one block right next to the switch (this is to stop the block and allow it to fall on the switch). Try to think backwards and work out where you need the block to come from to hit that final switch. You want to make an L shaped pathway for your final block using the other blocks as stopping stones which also change the direction of where your final block will go.
I'll try and give you an idea of this L shaped pathway:
Key
S - switch
[b] - block
(1)
a[B2]
aaaaaaaaaaaS[B3]
a[B1]
(2)
a[B2]
a[B1]
aaaaaaaS[B3]
(3)
a[B2]
aaaaaaaaa[B1][B3]
Mr_Stoukaph: third one is not that hard, try to work your blocks into a setup like I've shown above but you will need one that is one block distance from any of the edges so you have room to push the final block towards the switch.