We do not yet have enough experimental data to answer the question precisely, but there have been about one per century in the Milky Way (at least, the part that we can see). We know that there are supernovas in other galaxies, but they are detectable only through large telescopes.
6
Supernovas are the explosions of large stars in space.
36 years
3 years
The years 1776 and 2017 are 241 years apart. You can find this by subtracting 1776 from 2017, which gives you 241.
18
11
114
1500
4 years apart
In the Milky Way, a supernova occurs about once every 50 years.
Well since Bin Laden is still alive it cannot be known how many years apart they will die.