Question 491489
We want nC2 = 66 because the number of ways to choose two engineers to meet out of a pool of n is 66. Hence,


*[tex \LARGE \frac{n!}{(n-2)!2!} = 66]


*[tex \LARGE \frac{n!}{(n-2)!} = 132]


*[tex \LARGE n(n-1) = 132]


n = 12 engineers