Neeed help with an algebra question

If person A and person B weigh 175 pounds together and Person B and person C weigh a combined total of 150 pounds. How much heavier is person B than person C?

That's what i got

that's what i got

a + b = 175

b + c = 150 ----> b = 150 - c

now we got these twp equations

a + b = 175 (1)

b = 150 - c (2)

Subbing (2) in to (1)

a + 150 - c = 175

a - c = 25

a = c + 25 (3)

Subbing (3) in to 1

c + 25 + b = 175

c + b = 150

b = 150 - c

This means B is 150 more than c

So i guess C is equal to 0