Set the fan up high on the left, and the blow torch high up to the right. This is the tricky part (to explain also), take 2 balloons and place one each about 2 inches above each weight.
Then take rope from left balloon and attach to the right weight, then rope from right balloon to left weight, so the ropes cross over in the middle.
Then take the last balloon and turn it upside down and place it just above the weights and in between the other 2 balloons.
Of course you will need to adjust the heights of the Fan, so that it blows the balloon and weights to the right and the blowtorch should hopefully burst the balloons.