$10$ $years$ ago the average age of all the $25$ $teachers$ of the Girls college was $45\, years.$ $4 \,years$ ago, the principal has retired from her post at the age of $60 \,year.$ So after one year a new principal whose age was $54 \,years$ recruited from outside. The present average age of all the teachers is, if principal is also considered as a teacher

  • A

    $54 \frac{18}{25}$ years

  • B

    $55 \frac{17}{25}$ years

  • C

    $49 \frac{1}{2}$ years

  • D

    $49 \frac{2}{3}$ years

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