 
<translate> Otu tiketi e ji aga n'ọdụ ụgbọ okporo ígwè na-efu $3. N'ime otu nkeji, ụgbọ okporo ígwè na-ere nkezi nke tiketi 5 dị otú ahụ. Ego ole ka ị ga-enweta n'ego tiketi n'ime nkeji isii? Ka anyị buru ụzọ chee echiche. Ụzọ iche echiche: <eng> One ticket to the underground costs $3. In one minute, the metro sells an average of 5 such tickets. What will be the earnings from the tickets in 6 minutes? Let's think first. Chain of thought: 