Answer:
3 books
Step-by-step explanation:
She can carry 3 books in her backpack, this is because 1lb+3lb= 4
and if one book = 2lb each. Then 10-4 =6
so she has 6lb space remaning.
so 6lb divided by 2 = 3
1 bar is $1.50 because $3 divide 2 is 1.50
c= 1.50b
1= $1.50
2= $3
3= $4.50
4= $6