Question

Average of three numbers is 30. The first number is double of the second
and the third is double of sum total of first and second number.
What are the numbers ?​

Answer 1

ᴀɴsᴡᴇʀ

• Let second number be x

then, according to the question

• first number is 2x
• third number is 2(2x+x) = 6x
• and we have average of the numbers is 30

$\bold{average = \frac{sum \: of \: numbers}{no. \: of \: total \: numbers} }$

and here,

• average = 30
• numbers = x, 2x and 6x
• no. of total numbers = 3

$\bold{\implies 30 = \frac{x + 2x + 6x}{3} } \\ \\ \implies \bold{\: 30 = \frac{ \cancel{9}x}{ \cancel{3} }} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \implies \bold{30 = 3x} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \implies \bold{ x = \cancel{\frac{30}{3}} } \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \implies \bold{x = 10} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:$

so, second number is 10

then, first number is = 2 × 10 = 20

and third number is = 6 × 10 = 60

therefore, three numbers are;

• 10
• 20
• 60

Answer 2

Answer:

$\huge\mathfrak\red{\bold{\underline{☯︎{Solution}☯︎ }}}$

• see in the above attachment

$\huge\mathfrak\red{\bold{\underline{☯︎{Therefore}☯︎ }}}$

• First number is 20
• Second number is 10
• Third number is 60