Rosa needs to mail two packages one weighs five eighths of a pound and other ways two thirds of a pound what is the total weight of the to packages ? how much heavier is rosa second package than the first ?

The total weight of the packages is 5/8 = 0.625 + 2/3 =  0.666 i.e. 1.291 Pound.
TO be precise 2/3 would be 0.666666667, so technically the total weight of the two packages is 1.291666667 Pound.
To calculate the exact difference between Rosa's first and second package, we would have to subtract the weight of the second package with the weight of the first package: 0.666666667 - 0.625 = 0.041666667.
So, Rosa's second package is heavier by 0.041666667 pound.

So one weighs 5/8 and the other weighs 2/3 pound
make bottom number same
multiply 5/8 by 3/3 and multipy 2/3 by 8/8
5/8=15/24
2/3=16/24
add them together
15/24+16/24=31/24=1 and 7/24 pound
total weight is 1 and 7/24 pound

1st package=15/24
2nd package=16/24
subtract
16/24-15/24=1/24
the second package is 1/24 pound heavier

This is too long-standing now get out