Answer:
7140 pairs of key
Step-by-step explanation:
In calculating the number of pairs of keys required, the formula to be used is
n * (n−1) / 2
So for example, if we're to consider 120 users. This means our n is 120, and thus applying it in the formula would yield the calculation
120 * (120-1) / 2 =
120 * 119 / 2 =
14280 / 2 =
7140 key pairs.
Therefore, we boldly state that be number of pairs of key required is 7140