Answer:
10000
Explanation:
Assumed that the cost price of the item is x.
It was sold at a loss of 20%:
therefore the price sold was 0.8x
If it was sold at a profit of 10%:
the price sold would have been 1.1x
Since the difference in price is 3000:
1.1x - 0.8x = 3000
0.3x = 3000
x = 10000