The average age of Seema, Sapna, Asha, Kavita and Atrye is $40 \,years.$ The average age of Seema and Sapna is $35 \,years$ and the average age of Asha and Kavita is $42 \,years.$ The age of Atrye is?

The average age of $10$ men is increased by $2 \,years$ when one of them of $25 \, years$ age, is replaced by new man. What is the age of new man? (in $years$)

The average marks of a student in four subjects is $75 .$ If the student obtained $80$ marks in the $5^{\text {th }}$ subject then the new average is?

The average of $25$ results is $20 .$ the average of first $12$ results is $15$ and that of the last $12$ results is $18 .$ Then, the $13^{ th}$ results is

A student finds the average of ten $2 -$digit numbers. While copying numbers, by mistake, he writes one number with its digits interchaged. As a result his answer is $1.8$ less than the correct answer. The diference of the digits of the number, in which he made mistake, is

The average of consecutive numbers is $n .$ If the next two consecutive numbers are also included, the average of the five numbers will