Question 206811
A g (4 #/g) + 100 gms (7 #/g) = (A + 100)g * 6 #/g
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4A +700 = 6 (A+100)= 6A + 600
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100 = 2A
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50 g = A,,,,,,answer
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to  check,,50*4 +100*7 = (100+50)*6
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200 +700 =900 = 150 * 6 ,,,,ok
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