Question

The first shipping by company charges a fee of $20 to ship a medium box, plus an additional $1 per pound. A second company charges $15 for the same size box, plus an additional $2 per pound. At a certain weight, the two shipping methods will cost the same amount. How much will it cost

Answer 1

Total cost=$25

Explanation:

We can derive two expressions as follows;

Total cost for the First shipping company=Medium box charges+total additional charges

where;

Medium box charges=$20

Total additional charges=Charges per pound×number of additional pounds (n)

Total additional charges=1×n=n

replacing;

Total cost for the First shipping company=20+n....equation 1

Total cost for the second shipping company=Medium box charges+total additional charges

where;

Medium box charges=$15

Total additional charges=Charges per pound×number of additional pounds (n)

Total additional charges=2×n=2 n

replacing;

Total cost for the First shipping company=15+2 n....equation 2

Equating equation 1 and equation 2

15+2 n=20+n

2 n-n=20-15

n=5

Replace the value for n in equation 2

Total cost for the First shipping company=15+2 n....equation 2

Total cost=15+(2×5)=$25