The price of the lamp = $39.36
Explanation:
Original cost = $82
Discount = 20%
The discounted price = $82 × 20% = 82 × 0.2
The discounted price = $16.4
The price to be paid = $82 - $16.4 = $65.6
An additional discount of 40%:
Discounted price = 40% of $65.6 = 0.4 × $65.6
Discounted price = $26.24
The price of the lamp = $65.6 - $26.24
The price of the lamp = $39.36