The ratio of the arithmetic mean of two numbers to one of the numbers

Question

The ratio of the arithmetic mean of two numbers to one of the numbers is 3:5. What is the ratio of the lesser number to the greater?

(A) 1:5
(B) 1:4
(C) 1:3
(D) 2:5
(E) 1:2

TarunKumar1234 · Answer

Given, (a+b)/2a =3/5, where a>b

Now, (a+b)/a = 6/5, b/a = 6/5 - 1 =  1/5. A

Deyoz · Answer

IMO A.

let the two numbers be a and b.

we are given that  /b = 3x +5x (assuming that a<b)
3x =   and 5x = b
a+b = 6x 
therefore a = x
so, x/5x gives 1/5

MHIKER · Answer

Let, x and y are the numbers

\frac{x+y}{2}*\frac{1}{x}=\frac{3}{5}

=\frac{x+y}{2x}=\frac{3}{5}

=6x=5x+5y

=x=5y

=\frac{y}{x}=\frac{1}{5}

The answer is  A

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