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 $km / h$ ?
$5 \frac{9}{11}$
$11 \frac{5}{9}$
$9 \frac{5}{11}$
$5 \frac{5}{11}$
The average of three numbers of which greatest is $16$ is $12 .$ If the smallest is half of the greatest the remaining number is
The mean of $50$ observations was $36 .$ It was found later that an observation $48$ was wrongly taken as $23 .$ The corrected new mean is
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 $Rs. \, ?$
The mean of $19$ observations is $4 .$ If one more observation of $24$ is added to the data, the new mean will be
The average marks in English subject of a class of $24$ students is $56 .$ If the marks of three students were misread as $44,45$ and $61$ of the actual marks $48,59$ and $67,$ respectively, then what would be the correct average?