Maximum Quantity of Material A

Tom is planning a weekend project and needs to buy materials. He knows that the cost for each type of material can be expressed by the equation:

$$ C = 10x + 15y $$

where $$ C $$ is the total cost in dollars, $$ x $$ is the quantity of material A (which costs $10 each), and $$ y $$ is the quantity of material B (which costs $15 each). Tom wants to spend a maximum of $150 on materials. Write and solve an inequality to find the possible combinations of material A and material B that Tom can purchase.

What is the maximum amount of material A that Tom can buy if he buys no material B?