Answer:$400
Explanation:
Let them original price be cp
Selling price=340
Percentage decrease=15
Percentage decrease=(cp-sp)/sp x 100
15=(cp - 340)/cp x 100
Cross multiplying
15cp=100(cp-340)
Opening brackets
15cp=100cp-34000
Collect like terms
100cp-15cp=34000
85cp=34000
Divide both sides by 85
85cp ➗ 85=34000 ➗ 85
cp=400