Brooke will take 15 x 2 = <<15*2=30>>30 minutes to answer all math problems.
It will take him 6 x 30 seconds = <<6*30=180>>180 seconds to answer all social studies problems.
In minutes, this is equal to 180/60 = <<180/60=3>>3 minutes.
It will take him 10 x 1.5 minutes = <<10*1.5=15>>15 minutes to answer all science problems.
Therefore, Brooke will take 30 + 3 + 15 = <<30+3+15=48>>48 minutes to finish his homework.
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