Dan has $ 18. He bought 5 candy bar for $ 13 each one costing the same amount of money. How much money is left?
Dan has $18. 
He buys 5 candy bars for $13 each. 
That means he spends $65 in total on candy bars. 

Now we just need to subtract what he spent on candy bars from his original amount of money, which was $18. 

$18 - $65 = -$47

That means he would be left with -$47.