Step 1: The T.V.'s marked price is \( 24000/0.4=₹60000 \), so its selling price is ₹36000, and at \( 20\% \) profit its cost price is \( 36000/1.2=₹30000 \).
Step 2: The A.C. sells for \( 30000/0.6=₹50000 \), and since it carries a \( 20\% \) discount, its marked price is \( Y = 50000/0.8=₹62500 \).
Step 3: The Laptop sells for \( 50000 \times 1.5=₹75000 \), and since it carries a \( 30\% \) discount, its marked price is \( X = 75000/0.7=₹107142.86 \).
Step 4: Since \( 107142.86 \gt 62500 \), \[ \boxed{X \gt Y} \]