We are told that three packages are being mailed. Two of them weigh the same, and one is two pounds heavier. All three weigh 62 pounds.
Let w be the weight of one of the packages. Let's make w be the weight of the two packages that weigh the same amount. The third package, two pounds heavier, weighs w + 2 pounds.
Now we take our three packages - w, w, and w +2, and find their total weight. We are told they weigh 62 pounds.
w + w + w +2 = 62 <----weights of all three packages totaling 62 pounds
3w + 2 = 62 <----combine like terms
3w = 60 <----subtract 2 on both sides
w = 20 <----divide both sides by 3
We put w back into our weights of w, w, and w +2. So the packages weigh 20 pounds, 20 pounds, and 20 + 2 = 22 pounds.
Therefore the heaviest package weighs 22 pounds, and the other two weigh 20 pounds.