###Human: Ian spent half the money he made on doing online surveys. If he worked 8 hours doing surveys and on average he's able to earn $18 per hour doing surveys, how much money does he have left?, ### Assistant: Ian is able to earn $18 per hour doing surveys. If he worked 8 hours doing surveys, then he earned $18*8 = $144
If he spent half of what he earned, then he spent $144 * 50% = $72
If Ian spent $72 of his earnings, then he has $144 - $72 = $72 left 
 So the answer is :  72