cost of each at original price --- x
new price = x+15/100
10(x + 15/100) = 12x
10x + 3/2 = 12x
2x = 3/2
x = 3/4
original cost of pen was $.75 or 75 cents
check:
new cost = 90 cents
Is 10(90) = 12(75) ? YES
Mr Badger buy 12 pens for $x each. The price of the pens have now increased by 15
cents each. And he can only afford to buy 10 pens at the same total cost as before.
What was the original price of each pen?
1 answer
2 answers