Twenty caravans are travelling across the desert one day apart. The first caravan reached the oasis and the camels drank half of the water in the pool. On the second day. The second caravan reached the oasis and the camels drank one-third of the water that was left. On the third day. The camels in the third caravan drank one-quarter of the water that was left. On the first day the pool contained `1050 m^3` of water. How much water was left after the 20th caravan passed through.