How many distinct three-letter sequences with at least one $``T"$ can be formed by using three of the six letters of $TARGET?$ One such sequence is $``T-R-T."$
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
How many distinct three-letter sequences with at least one $``T"$ can be formed by using three of the six letters of $TARGET?$ One such sequence is $``T-R-T."$
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
48
How many distinct three-letter sequences with at least one $``T"$ can be formed by using three of the six letters of $TARGET?$ One such sequence is $``T-R-T."$
train