50% of a number when added to 50 is equal to the number.

Let the number be N.
According to the question,

	N + 50	+ 50 = N
	100

⇒	N	+ 50 = N
	2

⇒ N -	N	= 50
	2

⇒	N	= 50
	2

⇒ N = 100