The average of a collection of $20$ measurements was calculated to be $56\, cm .$ But later, it was found that a mistake had occurred in one of the measurements which was recorded as $64 \,cm ,$ but should have been $61 \,cm$. The correct average must be? (in $cm$)
$53$
$54.5$
$55.85$
$56.15$
The average of three consecutive odd numbers is $12$ more than one-third of the first of these numbers. What is the last of the three numbers ?
In a class, the average height of $35$ girls was measured $160 \,cm$. Later, on it was discovered that height of one of the girls was misread as $144\, cm ,$ while her actual height was $104 \,cm.$ What was the actual average height of the girls in the class? (in $cm$) (rounded off to two digits after decimal)
A batsman score $98$ runs in the $17^{\text {th }}$ match of his career. His average runs per match increase by $2.5$ What is his average before the $17^{\text {th }}$ match?
The average marks in English of a class of $24$ students is $56 .$ If the Marks of three students were misread as $44,45$ and $61$ in lieu of the actual marks $48,59$ and $67$ respectively, then what would be the correct average ?
The average salary per head of all workers of an institution is $Rs. \,60\,.$ The average salary per head of $12$ officers is $Rs. \,400 .$ The average salary per head of the rest is $Rs.$ $56 .$ Then, the total number of workers in the institution is?