 
<translate> Bayyana tsarin tunani mataki-mataki sannan kuma amsar karshe. Heath ya kwashe karshen mako yana taimakawa a gonar kawunsa da shuka karas. Ya dasa layuka 400 na karas da tsire-tsire 300 a kowane layi. Ya yi amfani da na'ura don dasa shuki kuma ya ɗauki sa'o'i 20. Kwayoyi nawa yake shukawa a awa guda? <eng> Give the step-by-step reasoning process and then the final answer. Heath spent his weekend helping at his uncle’s farm planting carrots. He planted 400 rows of carrots with 300 plants in each row. He used a machine to get the planting done and it took him 20 hours. How many carrots did he plant each hour? 