(b) ₹ 20000
Because,
Let the gross value of TV be ₹ x
Commission on TV = 10%
Price of the TV after deducting the commission = ₹ (x – 10% of x)
= (x – ((10/100) × x))
= (x – (x/10))
= (10x – x)/10
= (9x/10)
The price of TV after deducting the commission = ₹ 18000
= (9x/10) = 18000
= x = (18000 ×10) / 9
= x = (2000 × 10)
= x = ₹ 20000