text: Ok...no probs.  The best way to tackle this kind of problem is to keep to one variable, that way it ain't a variable if you see what I mean.  Let lot A = x, then lot B = x + 5000.  If lot C is 5000 more than lot B then lot C = x + 5000 + 5000\n\nSo lot A = x\n   lot B = x + 5000\n   lot C = x + 10000\n\nThe total of this is 3x + 15,000 and this equals 60,000\nSo if 3x + 15,000 =60,000   then 3x = 45,000 \nso x = 15,000 which,as you can see from the above is lot A.\n\nWhich shows that the book is correct.\n\nTo complete the problem B = 15,000 + 5,000 = 20,000\n                        C = 15,000 + 10,000 = 25,000\n\n25,000 + 20,000 + 15,000 = 60,000 correct!