Question 54735
(2.5+X).18=2.5*.11+X
.45+.18X=.275+X 
.45-.275=-.18+X 
.175=.82X 
X=.175/.82
X=.2134 METRIC TONS OF CHROMIUM NEEDS TO BE ADDED TO 2.5 TONS OF 11% TO RAISE THE % OF CHROMIUM TO 18%
PROOF 
(2.5+.2134).18=2.5*.11+.2134
2.7134*.18=.275+.2134
.488=.488 THE TOTAL AMOUNT OF CHROMIUM