The have run 12 laps because 6 + 6 = <<6+6=12>>12
They have run 1,800 meters because 12 x 150 = <<12*150=1800>>1,800
They have 600 more meters to run because 2,400 - 1,800 = <<2400-1800=600>>600
The have to run 4 more laps because 600 / 150 = <<600/150=4>>4
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