A fruit seller has some stock of fruits to be sold over a three-day period. Every day he sells 50 percent of the available fruits and 10 percent of the leftover fruits get spoiled during every night. If the total number of fruits that got spoiled in three days is 1983, then find how many fruits the seller had in the beginning.

The seller started with 24000 fruits.

Let the start be N; each day half is sold, then 10% of the remainder spoils overnight.

Night 1 spoilage = 0.10 x 0.5N = 0.05N, leaving 0.45N.

Night 2 spoilage = 0.10 x 0.225N = 0.0225N; Night 3 spoilage = 0.10 x 0.10125N = 0.010125N.

Total spoiled = (0.05 + 0.0225 + 0.010125)N = 0.082625N = 1983, so N = 24000.

Method: track the 45% survival factor across three nights.