Answer:
Let the cost price of the mobile set be Rs X
Then, Selling price of mobile set is 20% above the cost price = 120% of X = Rs (120/100)X = 1.2X
The discount given is 10%
Selling price after discount = 80% of Rs 1.2X
= (80/100)1.2X = 0.96X
Now we have selling price after discount = 0.96X
Gain = Rs 440
So, 0.96X - X = 44