Question

find it AMU BOOK
Not solved by teachers

Answer 1

Let the number be x

Its third = 1/3x

its quarter = 1/4x

its one-twelfth = 1/12x

so, its Average

$\implies \frac{ \frac{1}{3} x + \frac{1}{4}x + \frac{1}{12} x}{3} \\ \\ \implies \frac{ \frac{4x + 3x + x}{12} }{3} \\ \\ \implies \frac{ \frac{8x}{} }{3 \times 12} = \\ \\ \implies \\ \implies \frac{8x}{36} \\ \\ \implies \frac{2x}{9}$

Now, so here we get the average to be found as 2x/9

Now, Just apply hit and trial Method

So,Now take option (A)

•°• Apply the condition ,

Equate the relation with 1st option.

$\implies \frac{2x}{9} + 56 = 72 \\ \\\implies \frac{2x}{9} = 72 - 56 \\ \\ \implies \frac{2x}{9} = 16 \\ \\ \implies x = \frac{16 \times 9}{2} \\ \\ \implies x = 8 \times 9 \\ \\ \implies x = 72$

Here ,
\implies we get x=72

This means the equality holds.

Similirliraly , check all option there the equality will not holds

so,

$\huge{\bf{\blue{\colorbox{lime}{Answer : [A] 72}}}}$