The average of $8$ numbers is $20 .$ The average of first two numbers is $15 \frac{1}{2}$ and that of next three is $21 \frac{1}{3}$. If the sixth number is less than the seventh and eighth numbers by $4$ and $7$ respectively, then the eighth number is
$18$
$22$
$25$
$27$
There are three baskets of fruits. The $1^{st}$ basket has twice the number of fruits in the $2^{nd}$ basket. The $3^{rd}$ basket has three-fourths of the fruits in the first. The average of the fruits in all the baskets is $30 .$ What is the number of fruits in the first basket ?
A batch of $60$ students made an average score of $50$ marks and another batch of $40$ students made it only $45 .$ What is the overall average score ?
The average of certain first consecutive natural numbers is $20.5 .$ Find their sum.
Out of $9$ persons$, 8$ persons spent $Rs.\, 30$ each for their meals. The nineth one spent $Rs.\, 20$ more then the average expenditure of all the nine. The total money spent by all of them was (in $Rs.$)
The average salary of $15$ persons is $Rs.\, 5,500.$ If the salary of one person is added, the average increase to $Rs. \,5,700 .$ What is the salary of this one person in $Rs. \, ?$