Mr. Patel walked $6\,km$ to reach the station from his house, then he boarded a train whose average speed was $60 \,km / hr$ and thus he reached his destination. In this way he took total of $3\, hours.$ If the average speed of the entire journey was $32\, km / hr$ then the average speed of walking is (in $km/hr$)

The average weight of $45$ students in a class was calculated as $36 \,kg$. It was later found that the weight of two students in the class was wrongly calculated. The actual weight of one of the boys in the class was $32 \,kg ,$ but it was calculated as $34$ $kg ,$ and the weight of another boy in the class was $45 \,kg ,$ whereas it was calculated as $40 \,kg$. What is the actual average weight of the $45$ students in the class ? (in $kg$) (Rounded off to two-digits after decimal) 

The average weight of $A, B$ and $C$ is $84 \,kgs.$ If $D$ joins, the average weight now is $80 \,kgs$. If another person $E$ who is $3\, kgs$ heavier than $D$ replaces $A$ then the average weight of $B, C, D$ and $E$ becomes $79\, kgs.$ what is the weight of $A $ in $kg$ ?

In a school with $600$ students, the average age of the boys is $12$ $years$ and that of the girls is $11\, years.$ If the average age of the school is $11 \,years$ and $9 \,months,$ then the number of girls in the school is

The average of $41$ consecutive odd numbers is $49 .$ What is the largest number.