The average of the first $7$ integers in series of $13$ consecutive odd integers is $37 .$ What is the average of the entire series ?
$37$
$39$
$41$
$43$
A student bought $4$ books for $Rs. \,120$ from one book shop and $6$ books for $Rs.\, 150$ from another. The average price (in rupees), he paid per book was
The average age of four members of a family is $32\, years.$ If the age of a guest is included, then the average age increased by $12.5 \% .$ What is the age (in $years$) of the guest ?
A student finds the average of $10,2$ digit numbers. If the digits of one of the number is interchanged, the average increases by $3.6 .$ The difference between the digits of the $2 -$digit numbers is
The average weight of $45$ students in a class is $52\, kg.$ Five of them whose average weight is $48 \,kg$ leave the class and other $5\, students$ whose average weight is $54\, kg$ join the class. What is the new average weight (in $kg$ ) of the class
A person covers $9\, km$ with a speed of $3 \,km / h , 25 \,km$ with a speed of $5\, km / h$ and $30\, km$ with a speed of $10\, km / h$. Find out the average speed of person in $km / h$ ?