Use set notation to describe the venn diagram. here's the picture of the

The first picture represents the elements in B that are not (also) in A. So, we want the set difference of B and A:

For the second picture, we can work like this: if we take all the elements belonging to A, we only need to add the bottom-right part, which is the intersection of B and C. So, we can express the blue part as

4/6 = 2/3

so it should take 3/3 hours per man. so 9 hours is the answer 3*3 =9

step-by-step explanation: