Question 54735
1 metric ton = 1000 kg
This means initially Stainless Steel contains 11% Chromium by mass.
So 2500 kg of Stainless Steel contain {{{2500*11/100}}} = 275 kg of Chromium.
So the part other than Chromium = 2500 - 275 = 2225 kg.

Let us suppose 'x' kg of Chromium has to be added to raise its content from 11% to 18%.
Then final mass of Stainless Steel will be = (2500 + x) kg.
Out of this Chromium is 18% so the part which does not contain Chromium is (100 - 18) = 82%.
So part of the Stainless Steel other than Chromium = 0.82(2500 + x) kg.
But this is equal to 2225 kg.

So, 0.82(2500 + x) = 2225
or 0.82x = 175
or x = 213.42

So, 213.42 kg of Chromium has to be added.