New one:
1. Which Sentosa bus service connects the east of Sentosa to
Beach Station?
2. Which is the only Sentosa Volvo B7RLE with a
Mobitec EDS?
(Clue: Bus 2 perm)
3. Which SMRT bus service has all the Volgren O405s from that
particular depot?
4. Give me the first Batch 1 O405 with all the aircon ducts
inside the bus (including the door panels and driver's cab) that
have the Batch 2 black vents on the side.
5. Which 2 bus services serving Punggol Ter are not under HGDEP
control?
6. Which 190 perm Mobitec EDS O405 ever cameoed on 188R? (Note:
Still a KJDEP 190 bus)
7. Name me the bus service which is the longest trunk service.
(Clue: The 1st and 3rd digits are the same and one of these similar
digits is 3 more than the 2nd digit)
8. Which is the only Sentosa Volvo B7RLE with orange aircon ducts, like
the coaches? (Clue: Bus 2 perm, former Bus 3 perm)
9. Which Sentosa bus service gets very crowded, due to visitors
going from Imbiah Lookout to Underwater World?
10. Give me the Sentosa Bus 1 perm Volvo B7RLE which used to
serve the Yellow
Line. (Clue: MK II B7RLE)
Answers:
1. Bus 3 (Answered by user SMB128B)
2. PA4139M
3. RWS8 (except TIB958U, answered by user
SMB42P)
4. TIB542K (Repeated question! 
)
5. 3 and 136 (Answered by user SMB42P too)
6. TIB552G (Answered by user SMB42P as
well)
7. 858 (Answered by user TIB1173K)
8. PA5286P (actually, should be the only MK II, since RU3721U
[MK I] also have them )
9. Bus 1 (Answered by user SMB128B too)
10. PA5278M