The numbers are 17 and 18.
34, 35 and 36.
If there are two modes you add them and divide by two. Here are some tricks for other ways: 1.) If the two middle are consecutive (34,35) then you pick the middle which is (34,34.5,35 then your mode is 34.5). 2.) If the two numbers skip a number in between like (34,36) then the mode is the missing number which in this case is 35.
35 and 37.
17 and 18.
-33 -35 -37