Four oranges sell for Nx and three mangoes sell for Ny. Olu bought 24 oranges and 12 mangoes. How much did he pay in terms of x and y?

Analyze the question: The prices are given for groups of items (4 oranges and 3 mangoes), not for single items. So we need to find how many groups Olu bought.

Concept: If a group of items costs a fixed amount, then Total cost = (number of groups) × (cost per group).

Solution:

• Oranges: 4 oranges cost Nx. Number of groups in 24 oranges = 24 ÷ 4 = 6 Cost = N6x

• Mangoes: 3 mangoes cost Ny. Number of groups in 12 mangoes = 12 ÷ 3 = 4 Cost = N4y

• Total cost = N(6x + 4y)

Check against the options:

• A. "N94x + 6y)" is a typo-looking option and does not match.
• B. N(6x + 4y) matches our working.
• C and D would be correct only if each orange cost x and each mango cost y, which is not what the question says.

Tip: When prices are given for a group (like "4 oranges for Nx"), always divide the quantity bought by the group size first. Don't multiply the quantity directly by x or y. Options like C and D are traps for students who skip this step.