CSEC Mathematics · May/June 2013 · Paper 2 · Question 3(a)(ii)
A survey of 30 students in Form 5 showed that some students used cameras (C) or mobile phones (M) to take photographs. 20 students used mobile phones, 4x students used ONLY cameras, x students used BOTH mobile phones and cameras, and 2 students did not use either cameras or phones.
Write an expression, in terms of x, which represents the TOTAL number of students in the survey.
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