S. 37(1) : Business expenditure-Weighted deduction-R&D facility-Allowable as revenue expenditure-Interest on borrowed amount-Matter remanded-Exempt income-While computing disallowance under section 14A only average value of such investment from which yielded exempt income is to be considered. [S. 14A, 35(2AB), 36(1)(iii), R. 8D(2)(iii)]