Discussion

Explanation:

Roomesh bought 5 pens, 7 pencils and 4 erasers. Priya bought 6 pens, 8 erasers and 14 pencils for an amount which was half more what Roomesh paid. What % of the total amount paid by Roomesh was for the pens?

Let the cost of each pen, pencil and eraser be p, l and e respectively.

Amount paid by Priya is 1.5 times that of Roomesh
Let the total amount paid be Roomesh be T and that by Priya will be 1.5T.

Total cost of Roomesh = T =  5p + 7l + 4e   ...(1)
Total cost of Priya = 1.5T = 6p + 14l + 8e   ...(2)

(1) × 2 - (2)
⇒ 2T - 1.5T = 2(5p + 7l + 4e) - 6p + 14l + 8e
⇒ 0.5T = 4p
⇒ p/T = 1/8

Now, % of the total amount paid by Roomesh was for the pens = 5p/T × 100%
= 5 × 1/8 × 100% = 62.5%

Hence, option (b).

» Your doubt will be displayed only after approval.