The label on a bag of potato chips indicates that one serving contains 250 calories, with 150 calories from fat. what percent of calories comes from fat

250 represents the 100% of calories on the potato chips.
If you want to know the percentage that represents 150 calories from fat, then you have to multiply 150 calories (calories from fat) by 100% (the total percentage of calories) and then divide the outcome by 250 calories (the total calories on the potato chips):
(150 cal*100%)/250 cal= 60%