If it is assumed that 60 percent of those who receive a questionnaire by mail will respond and 210 responses are needed, what is the minimum number of questionnaires that should be mailed? Choose the correct option.
A) 290
B) 320
C) 350
D) 380
E) 410

Rationale: let x be the minimum number of questionnaires to be mailed . 0.6 x = 210 x = 350 the answer is c .
Answer: C