The difference between a single discount of 20% and two successive discounts of 16% and 4% on a bill of ₹50,000 is:

₹320

First discount = 20%

Successive discount = 16% and 4%

Successive discount =  x + y - \(\frac{x × y}{100}\)

Successive discount = 16 + 4 - \(\frac{16 × 4}{100}\) = 19.36%

Difference = 20 - 19.36 = 0.64%

= 0.64% of 50,000  = ₹320