Let total number of seats in the stadium be p; number of seats in the lower deck be x and number of seats in upper deck be y. ∴ p = x + y, x = p/4, y = 3p/4 Now in the lower deck, 4x/5 seats were sold and x/5 seats were unsold. No. of total seats sold in the stadium = 2p/3. No. of unsold seats in the lower deck = x/5 = p/20 No. of unsold seats in the stadium = p/3 ∴ Required fraction =