John weighs one-quarter times more than what Mary weighs. Mary weighs 20 lbs less than Jamison's weight. If Mary weighs 160 lbs, what's the combined weight of the three? Let's think first. Chain of thought:
If Mary weighs 160 lbs, Jamison weighs 160 lbs + 20 lbs = 180 lbs. If John weighs one - quarter less than what Mary weighs, he weighs 1 / 4 * 160 lbs = 40 lbs more. The total weight of John is 160 lbs + 40 lbs = 200 lbs. The total weight for the three is 200 lbs + 180 lbs + 160 lbs = 540 lbs.
Therefore, the answer is 540.