A women walks into a bank to cash out her check.
By mistake the bank teller gives her rupee amount in change, and her paise amount in rupees.
On the way home she spends 5 paise, and then suddenly she notices that she has twice the amount of her check.

How much was her check amount ?

Interesting Maths Puzzle

The check was for Rupees 31.63.
The bank teller gave her Rupees 63.31
She spent .05, and then she had Rupees 63.26, which is twice the check.

Let x be the rupees of the check, and y be the paise.

The check was for 100x + y paise
He was given 100y + x paise

Also
100y + x - 5 = 2(100x + y)
Expanding this out and rearranging, we find:
98y = 199x + 5

or 199x ≡ -5 (mod 98)
or 98*2*x + 3x ≡ -5 (mod 98)
3x ≡ -5 ≡ 93 (mod 98)
this quickly leads to x = 31