341. In the case of a benefit mentioned in section 340 and of a benefit granted under an income-averaging annuity contract and received as provided in the said section, the taxpayer may deduct that part of such benefit represented by the proportion that:(a) such part of any succession duties payable under a law of a province in respect of the death of the predecessor as, under such act, may be reasonably attributable to the property in payment or on account of which the benefit was so received is of
(b) the value of such property computed in accordance with such act.