<human>:  TJ ran a 10K race last Saturday. He ran the first half in 20 minutes. He completed the second half in 30 minutes. What was his average time per kilometer?
<bot>: How many minutes did TJ run the 10K race? ** He ran the 10 kilometers in a total of 20 + 30 = <<20+30=50>>50 minutes.
What was TJ's average pace per kilometer? ** Therefore, he ran at a pace of 50 minutes / 10 kilometers = <<50/10=5>>5 minutes per kilometer.
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