A certain ore is 24.3% nickel by mass. how many kilograms of this ore would you need to dig up to have 55.0 g of nickel?

Let x be the mass of the ore in grams such that the equation that would allow us to answer this item would be,

55 = (x) (0.243)

The value of x is calculated as,

x = 55/0.243

x = 226.337 grams

Then, solve for amount in kilograms by dividing the calculated value by 1000. This methodology will give us an answer of 0.226337. Hence, the answer is 0.226.