if i weight 75.6 on a scale and i pick up my cat and now i weigh 88.0 how much does the cat weigh

If picking up your cat causes you to go from weighing 75.6 to weighing 88.0, then the weight of the cat alone can be calculated by subtracting your initial weight (75.6) from the final weight (88.0):

Cat Weight = Final Weight - Initial Weight
= 88.0 - 75.6
= 12.4 pounds

Therefore, the weight of your cat would be approximately 12.4 pounds.