Are we always to assume semi-annual discount rate for zero-coupon bonds for the Exam?
If a 15-year, $1,000 U.S. zero-coupon bond is priced to yield 10%, what is its market price?
A) $23.50. B) $231.38. C) $239.39.
Yes…except when explicitly mentioned
I am sure the text will tell you explicitly all the terms needed to solve the questions. I don´t recall any questions where I had to make any assumtions in Level 1 and 2…that tactic has been reserved to make L3 more complicated 
Unless stated otherwise, yes