I have cleared 3 ct papers & took ct 2,5,6 last diet...now which one should I take ct 4 or 8...does ct8 need d knowledge of ct4....
CT8 needs a bit of CT4 knowledge. CT8 uses terms such as "stationary" and "Markov" that are introduced in CT4, and the last chapter of CT8 introduces a Markov jump process model for credit risk. The theory of Markov jump processes is in CT4. I'm sure CT8 is do-able without CT4 (and some students will have managed this), but I'd say ideally CT4 should be taken first, or they could be taken together.
Prior knowledge for CT8 counts for less than 10% of the entire subjects IMO.Best you go with a coin toss and work hard as there is no advantage of taking one before the other.