Acertain ore is 32.6% nickel by mass. how many kilograms of this ore would you need to dig up to have 75.0 g of nickel?

Note:
Nickel ore has a density of about 1.6 g/cm³.
This is equivalent to
(1.6 x 10⁻³ kg)/(10⁻² m/cm)³ = 1600 kg/m³

Because the ore yields 32.6% of nickel by mass,
1600 kg ore will yield 1600*0.326 = 521.6 kg of nickel.

Therefore, 75.0 g of nickel requires
[(75 x 10⁻³ kg)/(521.6 kg)]*(1600 kg ore)
= 0.23 kg ore

0.23 kg of ore