A computer memory has the capability of storing words. Due to outside forces, portions of the memory are often erased. Therefore, words are stored redundantly in various areas of the memory.

If a particular word is stored in n different places in the memory, what is the probability that this word cannot be recalled if one-half of the memory is erased by electromagnetic radiation?

These cells (boxes) may be located anywhere, geometrically speaking, in memory. The contents of each cell may be either erased or not erased. Assume n is small compared to the memory capacity.