Answer
The number is $\Longrightarrow$ 2
Work Step by Step
Let the number be 'x'
Reciprocal of x c $\frac{1}{x}$
Difference of 4 and x = 4 - x
Reciprocal $\Longrightarrow$ $\frac{1}{4 - x}$
Given:
$\frac{1}{x}$ = $\frac{1}{4 - x}$
Cross multiplying both sides,
1(4 - x) = 1(x)
4 - x = x
Adding 'x' on both sides,
4 - x + x = x + x
2x = 4
$\frac{2x}{2}$ = $\frac{4}{2}$ ....(Dividing both sides by 2)
Thus x = 2