$3 \,years$ ago the average age of a family of $5 \,members$ was $17 \,years,$ with the birth of a new baby, the average age of six members remains the same even today. Find the age of the new baby in $year$.
$2$
$3$
$5$
$7$
The average age of $10$ men is increased by $2 \,years$ when one of them of $25 \, years$ age, is replaced by new man. What is the age of new man? (in $years$)
The average speed of a cyclist who covers first, second and third km at $20,16$ and $12\, km / hr$ respectively ( in $km / hr )$ is
A man spends $Rs.\, 1800$ monthly on an average for the first four months and $Rs. \,2000$ monthly for the next eight months and saves $Rs. \,5600$ a year. His average monthly income is (in $Rs.\,$)
In an examination, out of $20$ students in a class, in Mathematics $2$ students scored $100$ marks $, 3$ students scored $0,$ and average marks for rest of the students was $40 .$ What is the average mark of the whole class ? (in $marks$)
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 $Rs.$)