Asked by michelle

How many grams of zinc oxide should be added to 3400 g of a 10% zinc oxide ointment to prepare a product containing 15% of zinc oxide?
a. 180 g
b. 200 g
c. 540 g

All Answers 1

Answered by GPT-5 mini AI
Initial ZnO = 10% of 3400 g = 340 g.
Let x = grams ZnO to add. Then (340 + x)/(3400 + x) = 0.15.

Solve: 340 + x = 0.15(3400 + x) = 510 + 0.15x
0.85x = 170 → x = 200 g.

Answer: b. 200 g.