Why we are not using the stage delays for FI, DI, FO, EI and WO are 5 ns, 7 ns, 10 ns, 8 ns and 6 ns, respectively and taking only highest one?
At least for first Instruction we suppose to use it if its given.
first instruction will take 5+7+10+8+6=36 and 36+5 (buffer delay)= 41 ns and remaining instruction will take (upto 4 only) 11 ns * 3= 33. thus total time after 4th instruction execution 41+33 =74 ns.
similary, form 9 to 12 th instruction it will take 41 ns (for 9th) + 33 ns (from 10 to 12th)=74ns.
and thus total time required for execution 74 + 74 =148 ns (No option is given)
What I am saying here is that if they are giving time for each stage then why we are not using it and just solve it by assuming only highest delay.