Answer: Rs 15,360

Solution:

For a sunglass,
Profit percentage (P%) = 20%
Selling Price with VAT (SP with VAT) = Rs 21,696
VAT percentage (VAT%) = 13%

To find: Cost Price (CP) = ?


We know,
SP = \dfrac{SP with VAT}{100 + \frac{VAT%}{100}}

or, SP = \dfrac{21696}{100 + \frac{13}{100}}

or, SP = \dfrac{21696}{\frac{113}{100}}

or, SP = 21696 × \dfrac{100}{113}

\therefore SP = Rs 19200


Now,
CP = SP(1 - \frac{P%}{100})

or, CP = 19200 ( 1 - \frac{20}{100})

or, CP = 19200 ( \frac{80}{100})

\therefore CP = Rs 15360

Hence, the shopkeeper bought the sunglasses at Rs 15360 and sold it.

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