Question

70. The average of three numbers is 52. The first is half of second and the second is twice the third.
The difference between the second and first number is
(1) 78
(2) 39
(3) 72
(4) 33
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Answer 1

Given :

Average of three numbers = 52

Let the third number be x.

According to the question,

Third => x

Second => 2x

First => $\dfrac{1}{2}$ (2x)

First => x

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Average = $\dfrac{x+2x+x}{3}$

52 = $\dfrac{4x}{3}$

$\dfrac{52*3}{4}$ = x

$\dfrac{156}{4}$ = x

39 = x

Hence,

numbers : 39,78,39.

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Verification :

$\dfrac{39+39+78}{3} = 52$

$\dfrac{156}{3} = 52$

LHS = RHS = 52

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Difference between the second and the first number :

Second number = 78

First number = 39

Difference = 78 - 39

Difference = 39.

Therefore option (2) is correct.

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