Question

a capsicum fruit has 200 viable seeds 1. write thre total number of megaspore mother cell involved in the production of 200 seeds

Answer 1

A total of 200 megastore mother cells would have been present. Each of them gives rise to 4 megaspores but only one of them becomes functional to form the gametophyte. So the number of seeds formed will be equal to the number of megaspores mother cells.

Answer 2

Okay simply putting 1MMC = 1 embryo sac.1 embryo sac = 1 seed.
The MMCs divide to form megaspores. 1 MMC divides meiotically to form four megaspores. Next only one megaspore survives. It's an evolutionary adaptation to conserve food materials for the growing embryo.
Coming to calculations 1 MMC gives 4 cells (haploid). One of the four survive to form the seed.