One of my friend is engaged in making investments in Bonds & securities. It earns exempt income from such investments. 91% of the total income is exempt income. Consequently, he is of the opinion of disallowing 91% of its total expenses u/s.14A stating that such expenses are related to exempt income.
Please suggest the appropriate method of calculating the amount of expense to be disallowed u/s.14A of the Income Tax Act, 1961.

