A sum of money is to be distributed among A, B, C, D with  ratio 5:2:4:3. If C gets 1000 more than D then what is the share of B?
Assuming that G.C.D. of (a, b) = 1.How can I prove that G.C.D. of ((a^2) - ab + b^2 ,a + b) =1 or 3?