Marked price of an item is Rs 500. On purchase of 2 items discount is 8%, on purchase of 3 items discount is 16%. Radha buys 5 items, what is the effective discount?

Marked price of item = Rs. 500

=> Marked price of 2 items = $$2 \times 500$$ = Rs. 1000

Amount saved on buying 2 items = $$\frac{8}{100} \times 1000 = Rs. 80$$

Marked price of 3 items = $$3 \times 500$$ = Rs. 1500

Amount saved on buying 3 items = $$\frac{16}{100} \times 1500 = Rs. 240$$

Thus, on buying 5 items, total amount saved = 80 + 240 = Rs. 320

Total marked price of 5 items = $$5 \times 500$$ = Rs. 2500

$$\therefore$$ Effective discount = $$\frac{320}{2500} \times 100$$

= $$\frac{320}{25} = 12.8 \%$$

=> Ans - (C)