Three year ago, the average age of a family of five members was $27 \,year.$ The present average age is also $27 \,year$ after the inclusion of a child into the family. Find the age of the child in $year$ ?
$16$
$12$
$24$
$20$
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 $n / m$ ?
In an entrance examination, Ritu scored $56$ percent marks, Smita scored $92$ percent marks and Rina scored $634$ marks. The maximum marks of the examination is $875 .$ What is the average marks scored by all the three girls together ?
Nine friends have a dinner in a hotel. Eight of them spent $Rs.\, 12$ each on their meals and the ninth spent $Rs. \,16$ more than the average expenditure of all the nine. Find out the total money in $Rs.$ spent by them?
The average of $11$ numbers is $10.9$ If the average of the first six is $10.5$ and the average of last six is $11.4,$ find the middle (sixth) number.
The average weight of a class of $24$ students is $35 \,kg$. If the weight of the teacher is included the average rises by $400\, g.$ The weight of the teacher is (in $kg$)