Also sir if for any reason we get the variances calculation wrong, then ofcourse our corresponding reasoning will also go wrong, in such a case would we be given marks for the reasoning used based on the “apparently incorrect” answer?
Assuming you are referring to Section C questions, then whatever the topic you do not lose marks twice for the same mistake. So if you make an incorrect calculation then you lose the marks for that one bit of the calculation but you still get full marks for any further calculations that need to use your wrong figure, and you still get full marks for correct discussion based on your wrong figure.