Average of three numbers is 28 . If first number is half of second and 3^{rd} number is twice second

English

Gujarati

Hindi

4.Average

medium

The average of three numbers is $28 .$ If first number is half of the second and the $3^{rd}$ number is twice the second, then the third number is?

A

$48$

B

$36$

C

$24$

D

$18$

Solution

Let the second number $=x$

$\frac{x}{2}+x+2 x=84 \Rightarrow \frac{x+2 x+4 x}{2}=84$

$7 x=84 \times 2 \Rightarrow x=\frac{84 \times 2}{7} \Rightarrow x=24$

Third number $=24 \times 2=48$

Standard 13

Quantitative Aptitude

Share

Similar Questions

What is the average of all numbers between $100$ and $200$ which are divisible by $13\, ?$

easy

The average marks of Sameer decreased by $1,$ when he replaced the subject in which he has scored $40 \,marks$ by the other two subjects in which he has just scored $23$ and $ 25$ marks respectively. Later he has also included $57$ marks of Computer Science, then the average marks increased by $2.$ How many subjects were there initially?

medium

A batsman in his $17^{th}$ innings, makes a score of $85$ runs, and there by, increases his average by $3$ runs. What is his average after the $17^{th}$ innings ? He had never been $'not out'.$

medium

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

easy

The average of $13$ results is $60 .$ If the average of first $7$ results is $59$ and that of last $7$ results is $61,$ what will be the seventh result $?$

medium