Let one pen, one pencil and one eraser cost = n, p, r units
Let the amount paid by me = A
∴IPay=(5n+7p+4r)=A..1
While Rajan pay (6n+14p+8r)=1.5A..2
Now multiply 1 by 2
we get
⇒(10n+14p+8r)=2A...3
Comparing 2 and 3 We see that while Rajan gets 4pen less ,he pays 0.5A unit less.
Thus A = the price of 8 pen
∴thepercentofthetotalpricepaidbymeinitiallywhichwasusedforpens=58×100=62.5