Question 924050
ore contains 20% zinc.
need 45 kg of zinc.


x = amount of ore


equation is .2 * x = 45
divide both sides of this equation by .2 to get:
x = 45 / .2
solve for x to get x = 225


he needs 225 kg of ore to get 45 kg of zinc.
.2 * 225 = 45