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A stud],r conducted at a factory manufacturing chemicals C; and Cr; yielded the following results. If a worker is exposed to either 01 or 02 {but not both), then the werker is at a low risk of developing a skin disorder. However1 if the worker is exposed to both Cl end 02, then he is at a high risk of contracting the skin disorder. If out of 370 workers in the factory, 320 are exposed to 01 and 90 are exposed to Cg, then how many workers are at high risk of developing the skin disorder? (Assume that ever worker is exposed to at least one of the two chemicals 0;, Cg.)