Out of four numbers, whose average is $60,$ the first one is one-fourth of the sum of the last three. The first number is
$15$
$45$
$48$
$60$
The average age of a class of $30$ students and a teacher reduce by $0.5 \,years$ if we exclude the teacher. If the initial average is $14 \,years,$ find the age of the class teacher in $year$ ?
If the difference between the average of $x, y$ and $y$, $z$ is $12,$ then the difference between $x$ and $z$ is
Find the average of the following set of scores $253,124,255,534,836,375,101,443,760$
The average marks of $120$ students are $35.$ If average of passed students was $39$ and failed students was $15,$ then Find the number of students who have passed?
The average speed of a train in the onward journey is $25\, \%$ less than that of the return journey, The train halts for one hour on reaching the destination. The total time taken for the complete to and fro journey is $17\, hours,$ covering a distance of $800 \,km$. The speed of the train in the onward journey is (in $km/h$)