What will be the cost of 27 tonnes of coal if 15 tonnes cost $360?

To determine the cost of 27 tonnes of coal when 15 tonnes cost $360, we first need to calculate the cost per tonne of coal.

The cost per tonne can be found by dividing the total cost by the number of tonnes:

Cost per tonne = Total cost / Number of tonnes

Cost per tonne = $360 / 15 tonnes = $24 per tonne.

Next, to find out the total cost for 27 tonnes, we multiply the cost per tonne by the number of tonnes we want to purchase:

Total cost for 27 tonnes = Cost per tonne x Number of tonnes

Total cost for 27 tonnes = $24/tonne x 27 tonnes = $648.

Therefore, the total cost for 27 tonnes of coal is $648, which aligns with the correct answer provided.