The average marks obtained by the students in a class are 43. If...

The average marks obtained by the students in a class are 43. If the average marks obtained by 25 boys are 40 and the average marks obtained by the girl students are 48 , then what is the number of girl students in the class?

Options

A $15$
B $17$
C $18$
D $20$

Correct answer

A. $15$

Step-by-step solution

Number of girls student be

x43=\frac{25 \times 40+x \times 48}{x+25}

\begin{aligned} & 43 x+43 \times 25=25 \times 40+x \times 48 \\ & 5 x=3 \times 25 \\ & x=15\end{aligned}

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