Answer : 15.5 pounds
To ship Liam's package using National parcel
The flat fee rate is $15.76
Let x be the weight of the items in pounds
THey charged $1.53 per pound
Total cost = flat rate charge + charge per pounds x the weight in pounds
Total cost = 15.76 + 1.53 * x
Total cost = 15.76 + 1.53x -------------- equation 1
Using Statewide shipping
It charges a flat fee of $19.48 and $1.29 per pound
Total cost = flat rate charge + charge per pounds x the weight in pounds
Total cost = 19.48 + 1.29 * x
Total cost = 19.48 + 1.29x --------------- equation 2
To calculate how many pounds Liam's package weigh for National Parcel's total charge to be the same as Statewide Shipping's total charge, then, we need to equate the both equation
Equate equation 1 and 2
15.76 + 1.53x = 19.48 + 1.29x
Collect the like terms
19.48 - 15.76 = 1.53x - 1.29x
3.72 = 0.24x
Divide both sides by 0.24
x = 3.72 / 0.24
x = 15.5 pounds
The amount of pounds must Liam's package weigh for National Parcel's total charge to be the same as Statewide Shipping's total charge is 15.5 pounds