Given,
CP of the article = Rs 170
Profit = 20%
So, by using the formula,
Selling price = (100 + Gain %)/100 × CP (0.5 Mark)
= (100 + 20)/100 × 170
= 120/100 × 170
= 204
SP = Rs 204 (1 Mark)
Discount = 15%
By using the formula
MP = (100 × SP) / (100 – Discount %) (0.5 Mark)
= (100 × 204) / (100 – 15)
= (100 × 204) / 85
= 20400/85
= Rs 240 (1 Mark)
∴ Marked Price = Rs 240