In a group of 12 engineers, 4 are 'Mechanical' engineers, 6 are 'electrical' engineers and the remaining are 'Civil' engineers. If 4 engineers are selected at random and the probability that at least one engineer is selected from each category is p/q then (p + q) lies between which the following interval?
1
70 to 75
2
76 to 80
3
81 to 85
4
86 to 90
5
91 to 95