Answer:
The retail price of the mattress before discount is $2400.
Explanation:
Given:
A furniture store pays a wholesale price for a mattress. Then, the store marks up the retail price to 150% of the whole price.
Later, they put the mattress on sale For 50% off though.
The customer just left the match is on sale and paid $1200.
Now, to get the retail price of the mattress before the discount.
Let the retail price of mattress before discount be

And the discount = 50%.
Price customer paid after discount = $1200.
Thus, according to question:






Multiplying both sides by 2 we get:

Therefore, the retail price of the mattress before discount is $2400.