A farm uses 15 harvesting machines to harvest 1800 \(kg\) of crops per day. Assuming all the machines work at the same rate, answer the following:
(a) How many kilograms of crops does one machine harvest in a day? \(kg\)
(b) How many kilograms will 30 machines harvest in a day? \(kg\)
(c) How many machines are required to produce 6000 kilograms of crops in a day? .