Co-owned property income is taxed by definite shares, with separate treatment for self-occupied and let-out house property. Income from co-owned property with definite and ascertainable shares is not assessed as income of an association of persons, but is computed separately according to each co-owner's share. For self-occupied property, each co-owner's annual value is nil and the interest deduction is available separately. For let-out property, income is computed as if owned by one owner and then apportioned among the co-owners according to their definite shares.