Question

Nathan and Steven stacked boxes on a shelf. Nathan lifted 13 boxes and Steven lifted 15 boxes. The boxes that Nathan lifted each weighed 12 lb more than the boxes Steven lifted.
Which expression represents the total number of pounds Nathan lifted?
Let s represent the weight of the boxes that Steven lifted.

13(s +12)**
s + 12
15(s + 12)
12(s + 13)

Answer 1

weight of single Steven box (English unclear) = s
so weight of a Nathan box = s+12
so weight lifted by Nathan = 13(s+12)
agree

but sentence could mean
total weight of boxes lifted by Steven = s
then each steven box weighs s/15

then a nathan box weighs (s/15) + 12
and total Nathan pounds =
13 [ (s/15) + 12 ]
= 13 s/15 + 156
since that is not a choice, go with your answer.

Answer 2

Thank you! :)

Answer 3

You are welcome :)