Hi,
8 Pckts each has 500 g weight .Total weight would be 8*500=4000g
and she arranged them into 3 boxes.
assume those three boxes are X,Y,Z first,second,thrid respectively.
X+Y+Z=4000g--------------------1
then according to the statement first box is twice heavy as second one
means X=2Y----------------2
and thrid box is 60g heavier than second box.
Z=Y+60--------------------3
put those values in to eq 1
2Y+Y+Z=4000
3Y+Y+60=4000
4Y=4000-60
4Y=3940
Y=985
second box weight is 985 gram
