The average age of four brothers is $12 \,year.$ If the age of their mother be also included, the average is increased by $5\, year.$ The age of the mother (in $years$) is

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 monthly expenditure of a family for the first four months is $Rs.\,2750$ for the next three months is $Rs.\,2940$ and for the last five months is $Rs.\,3130.$ If the family saves $Rs.\,5330$ throughout year, find the average monthly income of the family for that year. (in $Rs.$)

The average of two numbers is $62 .$ If $2$ is added to the smaller number, the ratio between the numbers becomes $1: 2 .$ The smaller number is

The average of $6$ numbers is $8.$ What is the $7^{th}$ number so that average becomes $10 ?$

What was the average in $Rs.$ daily expenditure of a man in $1999$ who spent $Rs. \,6535$ in the first half year and $Rs.\, 88165$ in the last?