The sum of three numbers is $98 .$ If the ratio between the first and second is $2: 3$ and that between the second and the third is $5: 8$ , then the second number is
$30$
$20$
$58$
$48$
The average of the boys in a class is $16\, years$ and that of girls is $15\, years.$ The average age for the whole class is
In an examination, out of $20$ students in a class, in Mathematics $2$ students scored $100$ marks $, 3$ students scored $0,$ and average marks for rest of the students was $40 .$ What is the average mark of the whole class ? (in $marks$)
The average of $6$ numbers is $3.95.$ The average of two of them is $3.4,$ while the average of the other two is $3.85 .$ What is the average of the remaining two numbers ?
Of the $3$ members whose average is $22 .$ What is the first number ?
The average salary of $20$ workers in an office is $Rs. \,1900$ per $month.$ If the manager's salary is added, the average becomes $Rs. \,2000$ per $month.$ The manager's annual salary (in $Rs.$) is