An air cooler costs Rs 3,300 including a value added tax of 10 per cent. What was its price before tax?

1. VAT is included in the quoted price, so Rs 3,300 is 110 per cent of the original. 2. If the pre-tax price is Rs 100, the paid price is Rs 110. 3. Original price = 3300 x (100/110) = Rs 3,000. 4. Check: 10 per cent of 3000 = 300, and 3000 + 300 = 3300. 5. Taking 10 per cent off 3,300 gives Rs 2,970, which is the standard trap. _Source: NCERT Class 8 Maths Ch7 'Comparing Quantities', Example 5_