Each ship holds 10 people, and the remaining 4 people.

So a *** 10x+4 person.

Each boat 12 people, there is one boat left.

X- 1 ship was used.

So a *** 12(x- 1) person.

So10x+4 =12 (x-1).

10x+4= 12x- 12

2x= 16

x=8

10x+4=84

Eight boats, 84 people.