Jennifer bought twice as many as Emily (who bought 6 candies) which is 6*2 = <<6*2=12>>12 candies
12 candies (that Jennifer bought) is three times as much as what Bob bought which means 3*what Bob bought = 12
Dividing both sides of the equation by 3 gives: Number of candies Bob bought = 12/3 = <<12/3=4>>4 candies
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