Erythroblastosis foetalis is an Rh incompatibility disorder. How is the problem usually averted?

Erythroblastosis foetalis is an Rh incompatibility disorder. Describe the circumstances in which erythroblastosis foetalis might arise.

In human beings, certain diseases are caused due to genetic disorders. How this method has been used for treating ADA (Adenosine deaminase) deficiency?

A dealer wishes to purchase a number of fans and sewing machines. He has only Rs. 5760 to invest and has space for at most 20 items. A fan costs him Rs. 360 and a sewing a machine Rs. 240. His expectation is that he can sell a fan at a profit Rs. 22 and a sewing machine at a profit of Rs. 18 . Assuming that he can sell all the items that he can buy,how should he invest his money in order to maximise the profit? Formulate this as a linear programming problem and solve graphically.