the answer is: each school picked up 12/128 tons
if I get the graph correct, every cross indicate the quantity under it. (an x above 1/8 means that there is 1/8 of a ton collected)
then, we need to add up the total amount of tons they collected.
we have 6 crosses in 1/8, 8 crosses in 1/4 and 2 crosses in 1/2. then we do:
[tex]6\cdot\frac{1}{8}=\frac{6}{8}=\frac{3}{4}[/tex][tex]8\cdot\frac{1}{4}=\frac{8}{4}=2[/tex][tex]2\cdot\frac{1}{2}=1[/tex]we add everithing:
[tex]\frac{3}{4}+2+1=3+\frac{3}{4}=\frac{12}{4}+\frac{3}{4}=\frac{15}{4}[/tex]the total amount of trash collected is 15/4 tons (3.75 tons)
there are 32 schools, then we need to divide the amount of trash by the amount of schools:
[tex]\frac{15}{4}\div32=\frac{15}{4}\cdot\frac{1}{32}=\frac{15}{4\cdot32}=\frac{15}{128}[/tex]every school got 15/128 tons of trash
