Q.A list price of ₹20,000 is offered with successive discounts of 10%, 5% and 5%. Find the net price and the equivalent single discount rate.

Apply the three discounts one after another to the reduced price at each stage, then find the equivalent single rate.

After $10\%$: $20{,}000\times0.9=18{,}000$. After $5\%$: $18{,}000\times0.95=17{,}100$. After a further $5\%$: $17{,}100\times0.95=16{,}245$.

Equivalent single discount $=\left(1-\dfrac{16{,}245}{20{,}000}\right)\times100=18.775\%$.

Here $L=₹20{,}000$, with three successive discounts $10\%$, $5\%$, $5\%$.

Step 1 — First discount ($10\%$).

Step 2 — Second discount ($5\%$), applied to ₹18,000.

Step 3 — Third discount ($5\%$), applied to ₹17,100.

So the net price is $N=₹16{,}245$.

Step 4 — Equivalent single discount rate.

As before, this is noticeably less than the naive sum $10\%+5\%+5\%=20\%$.

With three discounts in a row, a common shortcut error is applying the second and third discounts both to the ORIGINAL list price rather than each to the price left over from the previous step — for example, wrongly computing $20{,}000\times0.9\times0.95$ but then applying the final $5\%$ back onto $20{,}000$ again instead of onto the already-twice-discounted $17{,}100$.