Average age of student of an adult school is 40 years. 120 new students whose average is 32 years joined the school. As a result the average age is decreased by 4 years. The number of students of the school after joining of the new students is
Lets take number of students be \(N\). \(\) \begin{aligned} & \frac{N \times 40+120 \times 32}{N+120}=36 & 40 N+3840=36 N+4320 \end{aligned} \(\) \(\) 4 N=480 or N=120 \(\) So the total number of students after joining new students is \(120+120=240\)\[\]Choice (D) \[\]
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