The sum of three consecutive odd numbers is $38$ more than the average of these numbers. What is the first of these numbers

Out of nine persons$, 8$ 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 $Rs.\,$)

Out of three numbers, the first is twice the second and is half of the third. If the average of the three numbers is $56,$ the three numbers in order are

In an examination average marks obtained by the girls of a class is $85$ and the average marks obtained by the boys of the same class is $87 .$ If the girls and boys are in the ratio $4: 5,$ average marks of the whole class $(approx.)$ is closest to

A class has $20$ boys and $30$ girls. The average age of boys is $11\, years $ and that of girls is $12\,years.$ What is the average age of the whole class in $year$