5 Pens + 7 Pencils + 4 erasers= Rs X ......(1)
6 Pens + 14 Pencils + 8 erasers= Rs Y ......bought by rajan
ATQ ( Rajan bought 6 pens, 8 erasers and 14 pencils for an amount which was half more than what I had paid.)
Y = 1.5X
6 Pens + 14 Pencils + 8 erasers= Rs 1.5X......(2)
Also, 10 Pens + 14 Pencils + 8 erasers= Rs 2X ( from 1).....(3)
(3) - (2) => 4 pen = 0.5X
1 pen = 0.125X
=> 5 pens=0.625X
percent of the total amount paid by me was paid for the pens = 0.625X/X *100= 62.5 %