Provide your best answer for the following math problem. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The problem is: the probability that a man will be alive for 10 more yrs is 1 / 3 & the probability that his wife will alive for 10 more yrs is 5 / 8 . the probability that none of them will be alive for 10 more yrs , is
1 / 4
1/3 * 3/5 * (1-1/3) * (1-5/8) = 1/3