50 primary spermatocytes give rise to

Each primary spermatocyte undergo meiotic-I division and form 2 secondary spermatocyte. Each secondary spermatocyte undergo meiotic-II division and form 2 spermatozoa. Thus 50 primary spermatocyte X 2= 100 secondary spermatocytes:  100 secondary spermatocytes X 2 = 200 spermatozoa.