Below is an instruction that describes a task. Write a response that appropriately completes the request in Swahili. Please answer in Swahili.

### Instruction:
Gnuff charges a flat rate of $20 per tutoring session plus $7 per minute. The total amount paid for Gnuff for tutoring for one session is $146. How many minutes did Gnuff tutor for?

### Response:
 Kwanza, tunahitaji kujua kiasi ambacho Gnuff alitoza kwa ada ya kila dakika, ambayo tunapata kwa kutoa kiasi cha ada ya kawaida kutoka kwenye jumla ya kiasi kilicholipwa: $146 - $20 = $<<146-20=126>>126.
Kisha tunagawanya kiasi hiki kwa kiwango cha kila dakika ili kupata idadi ya dakika: $126 / $7 kwa dakika = <<126/7=18>>18 dakika.