A cricketer whose bowling average is $12.4$ runs per wicket takes $5$ wickets for $26$ runs and thereby decreases his average by $0.4$ The number of wickets taken by him till the last match was
$64$
$72$
$80$
$85$
The average temperature from Monday to Thursday is $48^{\circ} C$ and from Tuesday to Friday is $52^{\circ} C$. If the temperature on Monday is $42^{\circ} C$, what was it on Friday? (in $^{\circ} C$)
$10$ $years$ 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 professional institute's total expenditure on students for a particular course is partly fixed and partly varies linearly with the number of students. The average expense per student is $Rs.\,615$ when there are $24$ students and $Rs.\,465$ when there are $40$ students. What is the average expense when there are $60$ students ? (in $Rs.$)
Out of $30$ teachers of a school, a teacher of age $60$ $years$ retired. In his place another teacher of age $30$ $years$ was appointed. As a result, the mean age of the teachers will
A family consists of grand parents, parents and three grand children. The average age of the grand parents is $67\, years,$ that of the parents is $35\, years$ and that of the grand children is $6 \,years.$ What is the average age of the family? (in $years$)