Some are yes.
25 I believe.
The highest score you can get on the ASVAB is a 99
I just did a quick search online and found a plce where you can do the ASVAB prep. Military.com has it : http://www.military.com/ASVAB
After you are able to pass your practice ASVAB, you would schedule an appointment at your nearest MEPS to take the actual ASVAB.
you can get the information about asvab test study guide from the following website http://www.apexprep.com/asvab/
No. The ASVAB is used to determine what occupations you can be placed in.
Your local community college will show your local classes ASVAB test. You will need 80% percent in order to pass.
High school students can take the student ASVAB at their schools. The score is not used by the military. The ASVAB for enlistment is given at the MEPS, or you can arrange a CAT ASVAB through a recruiter.
Industries don't take the ASVAB people do, so I suspect you meant merchant mariner, but since merchant mariners are civilians they do not take the ASVAB
There are a number of sites that offer a free practice test or practice questions. Check out: http://www.military.com/ASVAB AND http://www.4tests.com/exams/examdetail.asp?eid=67 The first site has a lot of info on the significance of the test as well as tips on how to take it. You can find these at a number of sites. www.usmilitary.com/asvab-practice-test/ and military.com/ASVAB are merely two of many. sites.
You can find free ASVAB review materials here: http://www.testprepreview.com/asvab_practice.htm