Audrey was asleep for 10 hours last night and dreamed for 2/5 of the time. How much of the night was she not dreaming?
If Audrey was asleep for 10 hours last night and dreamed for 2/5 of the time, she dreamed for 2/5*10 = <<10*2/5=4>>4 hours.
The total time Audrey slept without dreaming is 10-4 = <<10-4=6>>6 hours.
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