Let Pencils Bought In Rs 15 = a

So the C.P of 1 pencil = Rs 15/a

Pencil Recieved By mr.X = a-3

Price of Each Pencil Which Mr.X has To pay=Rs (15/a-3)

According To Given Statement

15 - 15 = 0.25

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a-3 a

15 a - 15a +45 = 25

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a² - 3a 100

45 = 1

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a² - 3a 4

180 = a² - 3a

a² - 3a - 180 = 0

a² + 12a - 15a - 180 = 0

a(a + 12) - 15(a + 12)= 0

(a - 15)(a + 12) = 0

**a = 15 or a = -12**

No. of pencils Cane be negative So total No.Of Pencils = 15

But mr.X receives a- 3 pencil

**so, **

**Total No. Of Pencil Received By Mr.X = 15 - 3**

**= 12**