The average weight of $3$ person is $65 \,kg$. If a fourth person having a weight of $45 \,kg$ joins the group, what is the average weight of the group ? (in $kg$)
$65$
$63$
$61$
$60$
The sum of five numbers is $260 .$ The average of the first two numbers is $30$ and the average of the last two numbers is $70 .$ What is the third number ?
In a set of prime and composite numbers, the composite numbers are twice the number of prime number and the average of all the numbers of the set is $9 .$ If the number of prime numbers and composite numbers are exchanged then the average of the set of numbers is increased by $2 .$ If during the exchange of the numbers the average of the prime numbers and composite numbers individually remained constant, then the ratio of the average of composite numbers to the average of prime numbers (initially) was
The average age of a family of $6$ members is $22\, years.$ If the age of the youngest member be $7\, years,$ then what was the average age of the family at the birth of the youngest member?
The average of $50$ numbers is $30.$ If two numbers, $35$ and $40$ are discarded, then the average of the remaining numbers is nearly.
A batch of $60$ students made an average score of $50$ marks and another batch of $40$ students made it only $45 .$ What is the overall average score ?