If average of m numbers is n^{2} and that of n numbers is m^{2} , then average of ( m + n ) numbers

English

Gujarati

Hindi

4.Average

easy

If the average of $m$ numbers is $n^{2}$ and that of $n$ numbers is $m^{2}$, then the average of $( m + n )$ numbers is

A

$\frac{m}{n}$

B

$mn$

C

$m-n$

D

$m+n$

Solution

Sum of m numbers $=m n^{2}$, Sum of n number $=n^{2} m^{2}$

Average of $(m+n)=\frac{m n^{2}+n m^{2}}{m+n}=m n$

Standard 13

Quantitative Aptitude

Share

Similar Questions

$19$ persons went to a hotel for a combined dinner party. $13$ of them spent $Rs.\, 79$ each on their dinner and the rest spent $Rs.\, 4$ more than the average expenditure of all the $19 .$ What was the total money spent by them.

medium

With an average speed of $40\, km / h ,$ a train reaches its destination on time. If it goes with an average speed of $35 \,Km / h ,$ it reaches late by $15$ minutes. The total journey is (in $km$)

medium

A batsman scores $87$ runs in the $21^{st}$ match of his career. His average runs per match increase by $2.$ What is his average before the $21^{st}$ match?

medium

A cricketer whose bowling average is $12.4$ runs per wicket takes $5$ wickets for $26$ runs and thereby decreases his average by $0.4$ The number of wickets taken by him till the last match was

medium

What was the average in $Rs.$ daily expenditure of a man in $1999$ who spent $Rs. \,6535$ in the first half year and $Rs.\, 88165$ in the last?

medium