The average weight of four persons 'A', 'B', 'C', and 'D' is (6a + 3) kg. The weight of 'A' is 20% more than that of 'B' and the weight of 'D' is 40% more than the weight of 'B' whose weight is 20 kg less than the weight of 'C'. If the difference between the weight of 'A' and 'D' is a kg then find the value of 'a'?
1
6 kg
2
8kg
3
10 kg
4
12 kg
5
14 kg