 
<translate> Mrs. Fredrickson tana da zakaru 80 x 1 / 4 = 20. Don haka yana da kaza 80 - 20 = 60. Kawai 60 x 3 / 4 = 45 daga cikin kaji suna sa qwai. Saboda haka, 60 - 45 = 15 hens ba sa sa qwai. Saboda haka, Mista Fredrickson yana da duka kaji 15 + zakara 20 = kaji 35 da ba sa kwan. Amsar ita ce 35. <eng> Mrs. Fredrickson has 80 x 1 / 4 = 20 roosters. So he has 80 - 20 = 60 hens. Only 60 x 3 / 4 = 45 of the hens lay eggs. Thus, 60 - 45 = 15 hens do not lay eggs. Therefore, Mr. Fredrickson has a total of 15 hens + 20 roosters = 35 chickens that do not lay eggs. So, the answer is 35. 