when 40 is subtracted from 50% of a number, the result is 50% of 500. find one tenth of the number

Let the number be xxx. 50% of xxx is 12x\frac{1}{2}x21​x.
The statement “when 40 is subtracted from 50% of a number, the result is 50% of 500” becomes:

12x−40=12×500\frac{1}{2}x-40=\frac{1}{2}\times 50021​x−40=21​×500

12x−40=250\frac{1}{2}x-40=25021​x−40=250

Add 40 to both sides:

12x=290\frac{1}{2}x=29021​x=290

Multiply both sides by 2:

x=580x=580x=580

One tenth of the number:

110×580=58\frac{1}{10}\times 580=58101​×580=58

Answer: 58.