A number is first decreased by 10% and then increased by

A number is first decreased by 10% and then increased by 10%. The number so obtained is 50 less than the original number. The original number is

Let original number be x.

∴	90	x ×	110	= x - 50
	100		100

⇒	99x	= x - 50
	100

⇒ x -	99x	= 50
	100

⇒	x	= 50
	100

⇒ x = 5000
Aliter : Using Rule 3,
Let the number be x

Decrease % =	10²	% = 1%
	100

⇒ x – 1% of x =x – 50

	x	= 50 ⇒ x = 5000
	100