Q.A trader sells an article with a list price (sale price before tax) of Rs 1,500 at a sales tax rate of 8%. Find

The sale price and tax rate are given directly, so the sales-tax formula applies in one step.

Tax = Rs 1,500 × 8% = Rs 120. Total price = Rs 1,500 + Rs 120 = Rs 1,620.

Sale price P = Rs 1,500; rate r = 8%.

Sales Tax = P × r/100 = 1,500 × 8/100 = Rs 120.

Total price paid (tax-inclusive price) = P + Tax = 1,500 + 120 = Rs 1,620.

Check using the combined multiplier: P × (1 + r/100) = 1,500 × 1.08 = Rs 1,620 — matches exactly.

Alternative — compute the tax-inclusive multiplier once, 1 + 8/100 = 1.08, then 1,500 × 1.08 = 1,620 directly, reading off the tax as 1,620 − 1,500 = 120.

A common slip is computing the tax on the wrong base — e.g. taking 8% of the total price instead of the sale price before tax. This only matters once a problem gives the tax-inclusive price and expects you to work backwards (see the next example); here, since the sale price is given directly, 8% must be applied to Rs 1,500, not to any other figure.