Who collected the highest number of cans? Who collected the smallest number of cans? Naji and Chidi collected __ cans altogether. Usman and kufre collected __ more cans than Lodan. Is the total number of empty cans collected?

Here are the answers based on the pictograph:

First, let's count the number of cans collected by each person:

• Usman: 8 cans
• Bolaji: 6 cans
• Bilikisu: 9 cans
• Chidi: 7 cans
• Lodan: 3 cans
• Kufre: 10 cans

Now, let's answer the questions:

• a) Who collected the highest number of cans? Kufre collected 10 cans, which is the highest.

  $$\boxed{\text{Kufre}}$$

• b) Who collected the smallest number of cans? Lodan collected 3 cans, which is the smallest.

  $$\boxed{\text{Lodan}}$$

• c) Bolaji and Chidi collected cans altogether.

  $$6 \text{ (Bolaji)} + 7 \text{ (Chidi)} = 13 \text{ cans}$$ $$\boxed{13}$$

• d) Usman and Kufre collected cans altogether.

  $$8 \text{ (Usman)} + 10 \text{ (Kufre)} = 18 \text{ cans}$$ $$\boxed{18}$$

• e) Bilikisu collected more cans than Lodan.

  $$9 \text{ (Bilikisu)} - 3 \text{ (Lodan)} = 6 \text{ cans}$$ $$\boxed{6}$$

• f) What is the total number of empty cans collected?

  $$8 + 6 + 9 + 7 + 3 + 10 = 43 \text{ cans}$$ $$\boxed{43}$$