Let the money that the man has be x.
Money lost =20% of original money =20% of x=0.2×x
Money he has after losing = Original money − money lost
=x−0.2x=0.8x
After that, Money spent =25% of money after losing
=0.25×0.8x
=0.2x
Money Left = Money after losing − Money spent
=0.8x−0.2x=0.6x
But Money left is given as Rs. 480.
∴0.6x=480
⇒x=4800.6
∴x=800
so, he originally had Rs. 800.
OR
Since he loses 20% of the money, he is left with 80% of the money, which can be written as (80100)×x=0.8x
Now, he spends 25% of this money. So after spending, he is left with 75% of that money.
That would be (75100)×(0.8x)=0.6x
We are given that
0.6x=480
On solving, we get x = Rs. 800