variable cost

for june 12 num 4 variances i did not understand well y we must calculate the market share n size ?n how we must calculate it ?

Please do not ask questions on different topics under the same topic heading. Our answers are to help everyone - not just you - and if you put a variance question under the heading 'learning curve' other people might not find it.

For variable cost, I assume you mean the variable overheads? If you do, then because they are charged per labour hour, you use the same hours that you have calculated for the labour and multiply by the variable overhead rate per hour.

For June 2012, there is a sales volume variance because we actually sold 960 units but the budget was 1000 units. So we sold 40 fewer units than budget.

The question says that the market overall was down by 10% and so we would have expected to sell 10% fewer units as well - 10% of the budgeted 1000 means that we would have expected to see 100 fewer units (which is 900).
So why did we actually sell 960 units and not 900? It must have been because we gained market share and this gained us 60 units.

So....we knew we were 40 units less. We now know that 100 units less is because of the market overall being smaller, but 60 units more is because of having more market share.
We cost them both out at standard contribution as we always do for the sales volume variance.

sory may b i was doin a kestion on learning curve so i didnot pay attention :(

No problem :)