First figure out how much the first babysitter costs by multiplying her hourly rate by the number of hours she works: $16/hour * 6 hours = $<<16*6=96>>96
Then use the same method to figure out how much the second babysitter charges before any screaming: $12/hour * 6 hours = $<<12*6=72>>72
Then figure out how much the babysitter charges for two screams: 2 screams * $3/scream = $<<2*3=6>>6
Finally, subtract the second babysitter's two charges from the first babysitter's total charge to find the difference: $96 - $72 - $6 = $<<96-72-6=18>>18
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