Charlie hits the target 80 times in 100 shots.

probability/hit.target New

New entry, edited from material collected for the archive and not yet in a released version.

Problem

Charlie hits the target 80 times in 100 shots.  Jim hits the target 90
times in 100 shots.  What are the chances that the target is hit, if
each fires once?

Show solution

If Charlie misses 1/5 of the time and Jim misses 1/10 of the time, then
they will both miss 1/50 of the time, so the probability that the target
will be hit at least once is 49/50 or 98%.

-- Mike Naylor <mike.naylor@mail.serve.com>

[ Editor: the problem was posted by Philip Carter <philip@knowl.demon.co.uk>.
The answer assumes the two shots are independent. ]