The mean score in a test of the 12 boys in a class was 16 while the overall mean of the 30 students in the class was 18.1. What was the mean score of the girls?
The correct option is D.
Number of girls = 30-12=18Â
let the mean score of girls = $$x$$
then, $$\frac{12\times16+18\times x}{30}$$ = 18.1
$$\implies$$ 192 + 18$$x$$ =543
$$\implies$$ 18$$x$$= 543-192 = 351
         $$x$$ = 19.5
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