 <translate> E nwere 80 / 2 = 40 wireless òké rere. E nwere 80 / 4 = 20 optical òké rere. Ya mere, e nwere ngụkọta nke 40 + 20 = 60 wireless na ngwa anya òké rere. N'ihi ya, e rere 80 - 60 = 20 trackball mice n'ọnwa a. Ya mere azịza ya bụ 20. <hau> Akwai 80 / 2 = 40 marasa waya da aka sayar. Akwai 80 / 4 = 20 linzamin kwamfuta da aka sayar. Don haka, an sayar da jimillar 40 + 20 = 60 na wayoyin mara waya da na gani. Saboda haka, 80 - 60 = 20 an sayar da berayen trackball a wannan watan. Amsar ita ce 20. 