We let x be the weight of the red bag, y for the green bag and z for the pink bag. It was given that the total mass of the 3 bags is 32 pounds. Thus,
x + y + z = 32
It was given that the red bag or x weighs 93/4 pounds and the green bag or y weighs 1/12 of the red bag. Substituting the values given, we have:
(93/4) + (1/12)(93/4) + z = 32
z = 6.8125 lbs
Thus, the pink backpack weighs 6.8125 pounds.