Mixture D is 20% oil and 80% material B by weight. If 2 more kilograms of oil are added to the 8 kilograms mixture D, how many kilograms of mixture D must be added to make a 70% material B in the new mixture?
Choose the correct choice from the following.
A) A)6 B) B)7 C) C)8 D) D)9 E) E)10
Can be done with weighted avg method.   if 2 kg more of oil is added to 20% oil of 8 kg mix,then a 10kg of mix will have 3.6kg (or 36%) of oil .   D1=20(initial mix.)   Avg. is what we need..ie 70% of material B means 30% of oil   D2=36(36% of 10 kg mix)   w1/w2=(D2-Avg)/(Avg-D1)   (36-30)/(30-20)   6/10   means for every 10 kg of new mix. we need 6 kg of mix D   6ns 6
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Mixture D is 20% oil and 80% material B by weight. If 2 more kilograms of oil are added to the 8 kilograms mixture D, how many kilograms of mixture D must be added to make a 70% material B in the new mixture?