questions in CCNA sem4 ?

Ask your instructor - there's no reason why he/she should not have previewed the Final Exam - I assume that's what you mean. Hint, each of the four semester Final Exams have around the same number of questions.

I always tell my students how many of each questions type there is - I use the exam to test their knowledge not to see how they cope with surprises - besides which we usually weight the Skills Based Assessment much more than the Exam anyway - but that's up to your Academy's policy not me.

How tough is it - well if you have a reasonably thorough knowledge of NAT/PAT, DHCP, ISDN, Frame Relay & PPP and have done the labs it's not that difficult to get the 80% pass we require, but if you don't have that knowledge then ....

You would be better off reviewing the curriculum and the e-labs instead of sweating administrative stuff you don't know - unless you're preparing an excuse for failing - I assume that you got to this stage of the course legitimately, in which case just apply the same effort to CCNA 4 and you'll be fine.

Aubrey