There are 4 circles A,B,C & U representing sets, 3 of them (A,B,C) intersecting each other.... A is set of red objects, B is set of blue and C is set of yellow.... U is said to be a universal set.. U circle is in the isolation of the other 3 intersecting none.... Draw a Venn diagram.... { I've got a pretty good idea about A,B,C but cannot understand the position of U in the diagram and what do ' in isolation of other 3 intersecting none means'....??}