What's the odd number in 21,34,67,120,78,87

Can someone me with this problem . show your work .

Which basic geometric term has no width, no length, and no thickness? line b. point c. angle d. plane

If you can solve all of these i will give ! - 4% of 190 - 4% of 162.5 - 4% of 140 - a 4% increase from 155.1 - a 4% increase from 159.8