Really need to know the concepts in and out well. I panicked at the Binomial Tree because in my preparation I thought how hard can those questions be? I even memorized all the formulae related to that topic only to realize that the USD/CAD question is not as straightforward as a European call option valuation question. I applied the discount factor wrongly. Instead of letting the discount factor be exp(-rt) i let it be exp-(r-rf).
Yeah - I'll definitely have to change the way I prepare and attempt the exam. I was only at question 11 at the first 1/2 hour mark, so I probably rushed a bit much through the rest of the exam. The FX-related Binomial question through me off too. I didn't have a chance to think it through all of the way...