Q$.1$ X Ltd$.$ produces four versions $($A$,$ B$,$ C and D$)$ of the same product. Each version is a modification of the version $A,$ the basic version of the product. A particular assembly line can produce all the four varieties of the product. The assembly line can produce $10,000$ units of the same version of the product at a time. The set$-$up cost is Rs$.10,000$ per set$-$up$.$ On the basis of the pattern of market demand, X Ltd$.$ produces $10,000$ units of A$,5,000$ units of B$,2,500$ units of C$,$ and $1,000$ units of D$.$ Determine set up costs to charged to the different versions A$,$ B$,$ C and D using:

$($a$)$ Traditional method of charging overheads.

$($b$)$ Activity$-$based costing method