###Human: It's Yvette's turn to treat herself and her three best friends to a round of ice cream sundaes.  Alicia orders the peanut butter sundae for $7.50.  Brant orders the Royal banana split sundae for $10.00.  Josh orders the death by chocolate sundae for $8.50 and Yvette orders the cherry jubilee sundae for $9.00.  She leaves her waiter a 20% tip.  How much will her final bill be?, ### Assistant: Yvette spent 7.50+10+8.5+9 = $35.00 on ice cream sundaes
Her bill comes to $35.00 and she leaves a 20% tip for the waiter so that's 35*.20 = $7.00
The bill was $35.00 and she added a $7.00 tip for a total of 35+7 = $42.00 
 So the answer is :  42