A wholesaler's invoice shows goods worth ₹18000 plus ₹2000 of freight, and he offers 10% off. If the 10% is worked out on the whole invoice instead of on the goods value alone, the buyer pays less by (in ₹):

On the goods alone the discount is ₹1800 and the buyer pays 20000 − 1800 = ₹18200. On the whole invoice it is ₹2000 and he pays ₹18000. The difference is ₹200 — exactly 10% of the ₹2000 freight, which is the only amount treated differently by the two rules. (Two successive PERCENTAGE discounts may be taken in either order without changing the total, and that familiar fact makes ₹0 tempting; here the question is not about order but about what the percentage is applied TO. ₹1800 and ₹2000 are the two discounts themselves, not the gap between them.)