Ashish has earned an average of $4200$ dollars for the first eleven months of the year. If he justifies his staying on in the US on the basis of his ability to earn at least $5000$ dollars per $month$ for the entire $year,$ how much should heearn (in $dollars$) in the last $month$ to achieve his required average for the whole $year$ ?
$14600$
$5800$
$12800$
$13800$
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 $years$)
An aeroplane travels $2500 \,km , 1200 \,km$ and $500\,km$ at $500\, km / h \,, 400 \,km $ and $250\,km / h $ respectively. The average speed is:(in $km/h$)
A professional institute's total expenditure on students for a particular course is partly fixed and partly varies linearly with the number of students. The average expense per student is $Rs.\,615$ when there are $24$ students and $Rs.\,465$ when there are $40$ students. What is the average expense when there are $60$ students ? (in $Rs.$)
The average of three numbers is $154 .$ The first number is twice the second and the second number is twice the third. The first number is
Mr. Patel walked $6\,km$ to reach the station from his house, then he boarded a train whose average speed was $60 \,km / hr$ and thus he reached his destination. In this way he took total of $3\, hours.$ If the average speed of the entire journey was $32\, km / hr$ then the average speed of walking is (in $km/hr$)