Question 1134469
To create the venn diagram, I noted that the total needs to be 100 and we have 10 on the outside who did not fall into any of the categories.  Since 45 smokers lived in urban areas, but 37 did not have a hazardous occupation, that puts the 37 in the sm and u overlap and 8 (45-37) in the area where all 3 overlap.  20 people have a haz occupation, of whom 10 live in urban.  8 of those 10 were already accounted for leaving just 2 to be in u and ho overlap.  Same is true for the 10 who smoke.  With a total of 20 in HO, 12 have been assigned, leaving 8 for just HO.  Last to fill in was just the U.  All the values were added together for 85.  We need 90 in the circles, so 5 are in the U only part.
i.  8
ii. 2+8+37+5 = 52
iii. 28+37 = 65
iv. 8