A merchant has 100 lbs of sugar, part of which he sells at 7% profit and the rest at 12% profit. He gains 10 % on the whole. Find how much is sold at 7% profit?	Options.
A) 70 lbs
B) 40 lbs
C) 30 lbs
D) 50 lbs
E) 60 lbs
These types ofweighted averagequestions can be solved in a variety of ways, so you can choose whichever method you find easiest/fastest. Here's another variation on the Weighted Average Formula:   A = # of pounds sold at 7% profit   B = # of pounds sold at 12% profit   A+B = 100 pounds   (.07A + .12B)/(A+B) = .10   .07A + .12B = .1A + .1B   .02B = .03A   2B = 3A   2/3 = A/B   So, for every 6 pounds of A, we have 4 pounds of B.   With 100 pounds total, we have 40 pounds of A and 60 pounds of B.   Option 40 lbs
<result>B</result>
A merchant has 100 lbs of sugar, part of which he sells at 7% profit and the rest at 12% profit. He gains 10 % on the whole. Find how much is sold at 7% profit?