85n >/= 1,045
85 people times n buses has to equal or exceed 1,045 people
85n is greater than or equal to 1,045
85n >/= 1, 045
n >/= 12.29
So, since n has to be greater than or equal to 12.29, and there is no 29/100ths of a bus, they would need 13 buses (in case there's a follow-up question)