The average of $6$ numbers is $3.95.$ The average of two of them is $3.4,$ while the average of the other two is $3.85 .$ What is the average of the remaining two numbers ?
$4.5$
$4.6$
$4.7$
$4.8$
Out of nine persons, eight persons spent $Rs. \,30$ each for their meals. The ninth one spent $Rs. \,20$ more than the average expenditure of all the nine. The total money spent by all of them was (in $Rs.$)
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 $Rs.$)
Three years ago the average age of a family of $5$ members was $27\, years.$ On addition of a child to the family, the present average age of the family is still $27 \,years.$ Find out the present age of the child. (in $years$)
There are three baskets of fruits. The $1^{st}$ basket has twice the number of fruits in the $2^{nd}$ basket. The $3^{rd}$ basket has three-fourths of the fruits in the first. The average of the fruits in all the baskets is $30 .$ What is the number of fruits in the first basket ?
The mean weight of $34$ students of a school is $42 \,kg$. If the weight of the teacher be included, the mean rises by $400 \,g$. Find the weight of the teacher (in $kg$).