91. What is meant by payscale structure? How did you configure payscale structure? (I said I created various payroll areas and defaulted them using the feature ABKRS. Seemed he was expecting more than this from me.)

Pay Scale Structure means creation of Payroll area , Pay scale type, area, group and levels with EmpSub group grouping for PCR & CAP's.

92.  How do you import payscale data from non SAP to SAP? (Somebody told me that there's a tool called LEGACY to transfer non SAP data to SAP. I said the same. Is it the same for payroll also? He wanted a clearer explanation of how I did it.

Yes you have to say from which transaction code you are transferring data from Non SAP in to sap. 

93.  How to assign a person two different pers no.s and allocate him two different comp. codes and generate a single invoice? Suppose for a person I have to pers no.s A and B. I want to send him to one company in the morning and the other in the noon. How should I do this. (I only know one person can be given more than one position by giving percentage in OM. I said that this process is concurrent employment.)

No, even with Concurrent employment also it is not possible to assign two personnel numbers for one person. You can assign him to work with two Personnel ID Numbers with the same number and make invoice.

94. What is meant by a schema? (I said I'm only aware that it is a set of rules which is copied and renamed, but never worked on that.)

No, you have to say him that schema is a set of instructions (Programs)  modified as per requirements and its process is to collect the data as from all the defined instructions with sub schemas and PCR's. As I was not authorized to work on them I know just the process of schemas only, (you should have said like this.) 

95. How do you restrict the data to be entered in payroll area?

No, data is entered in a payroll area, but the employees are defined depending on their payscale structure. If you are restricting any data to be entered for pay strcs this is for indirectly for payroll area.

96. What is meant by authorization? Did you ever work on it?

Authorisations are the transactions given to the end users or the developers for only some areas to work, infotyopes, transaction codes, org units and others depending on the requirement of the client or the developing enterprise.  Check this at PFCG tcode.

97.  What is the difference between Indian and US Payroll? (I said each of them has their own ITs and the taxation differs.)

Yes it correct and even you have to say about the Benefits which are more important in US. In US unemployment tax will come. Garnishments will come, Residence taxation, Work tax and others, you have to say it in broad way then only they can know that you are working, or confident enough.

98. Give me a brief description of the IT Tax.

No IDEA.

99. How do you differentiate Tax for different countries?

Taxation has so many use exits to be created which means it all happens only from the new versions which SAP Releases.

100. What is meant by slab? How is Indian slab and US slab? (He was talking about some %ages. I don't know what they are.) 

Grouping of employees depending on their allowances and PERKS is nothing but Slab system and it also even comes for Professional Tax.