Maths Problem - How to explain solution

[elevenplusprep]

Hi,

I had come across one maths problem in one of the test papers which is following

3 baby elephants weight worth of coal is utilised to light one 100 watt bulb for 24 hours for 30 days. How many 100 watt bulbs would be required to burn 12 baby elephant weight worth of coal if bulbs are burned 12 hours for 30 days?

I know answer is 8 but I am not able to explain the steps to get the solution to my DS. Can anyone help in explaining the solution?

Thanks

[poiuyt]

4 times the elephants for half the time, makes 8 bulbs

[yoyo123]

diagrams are a great help when trying to explain anything