If property is so disposed of that the right of a beneficiary to succeed to any interest therein is conditional upon his surviving another person, and both persons die, and there is no sufficient evidence to establish that the two have died otherwise than simultaneously, the beneficiary shall be deemed not to have survived. If there is no sufficient evidence to establish that two or more beneficiaries have died otherwise than simultaneously and property has been disposed of in such a way that at the time of their death each of such beneficiaries would have been entitled to the property if he had survived the others, the property shall be divided into as many equal portions as there were such beneficiaries and these portions shall be distributed respectively to those who would have taken in the event that each of such beneficiaries had survived.