budgeting

Hi sir Please look at this question.i know how to do both of them.just a small doubt 1.CA Co manufactures a single product and has drawn up the following flexed budget for the year. 60% 70% 80% $ $ $ Direct materials 120 000 140 000 160 000 Direct labour 90 000 90 000 120 000 Production overhead 54 000 58 000 62 000 Other overhead 40 000 40 000 40 000 Total cost 304 000 343 000 382 000 What would be the total cost in a budget that is flexed at the 77% level of activity. in this question we only take prod. o/h and do the high low method. 2. Qt co manufactures a single product and aan extract from their flexed budget for production costs is as follow 80% 90% Direct Mat. 2400 2700 lab 2120 2160 Prod O/H 4060 4080 what wud be the total prod cost allowance in a budget flexed at 83 % level of activity?? in this question we take labour and prod o/h and do the high low method to find variabe and fixed costs. how do we come to know what all things to include when finding the variable cost using high low?