Martha has 11 butterflies in her collection. She has twice as many blue butterflies as yellow butterflies. The rest of her butterflies are black. If Martha has 5 black butterflies, how many blue butterflies does she have?
Martha has 11-5=<<11-5=6>>6 blue and yellow butterflies.
Martha has 6/3=<<6/3=2>>2 yellow butterflies.
Martha has 2*2=<<2*2=4>>4 blue butterflies.
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