The average age of $11$ players of a cricket team is increased by $2 \,months$ when two of them aged $18\, years$ and $20 \,years$ are replaced by two new players. The average age of the new players is?

In an examination average marks obtained by the girls of a class is $85$ and the average marks obtained by the boys of the same class is $87 .$ If the girls and boys are in the ratio $4: 5,$ average marks of the whole class $(approx.)$ is closest to

A batsman makes a score of $8$ runs in the $16^{\text {th }}$ match and thus increases his average runs per match by $3 .$ What is his average after the $16^{\text {th }}$ match?

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 ?

The average age of $36$ $students$ in a group is $14\, years.$ When teacher's age is included to it, the average increases by one what is the teacher's age in $years$ ?