The average monthly salary of $20$ employees in an organisation is $Rs.\, 1500$. If the manager's salary is added, then the average salary increases by $Rs.\,100.$ What is the manager's monthly (in $Rs.$)
$2000$
$2400$
$3600$
$4800$
The average marks of a group of $20$ students on a test is reduced by $4$ when the topper who scored $90$ marks is replaced of a new students. Find the marks of the new student.
The average age of four members of a family is $32\, years.$ If the age of a guest is included, then the average age increased by $12.5 \% .$ What is the age (in $years$) of the guest ?
Out of four numbers the average of the first three is $16$ and that of the last three is $15 .$ If the last number is $20$ then the first number is
In a $20$ over match, the required run rate to win is $7.2 .$ If the run rate is $6$ at the end of the $15^{th}$ over, the required run rate to win the match is
The average of the test scores of a class of $'m'$ students is $70$ and that of $'n'$ students is $91.$ When the scores of both the classes are combined, the average is $80 .$ What is $n / m$ ?