thanks for the answers, i am happy with what i have... i am now sure the question is designed to dilineate two levels of students, and so there's no need for me to progress further for now.
thankyou delta2
i bungled the second equation... should be 9 / 0.00033 of course
answer i get is 2.7*10^4
but the mcq answers are...
a) 9.0*10^3
b) 5.3*10^4
c) 2.4*10^5
d) 1.6*10^6