Mark hires a singer for 3 hours at $15 an hour. He then tips the singer 20%. How much did he pay? Give the rationale and then the answer.
Let's think step by step. The cost was 15 * 3 = $45. So the tip was 45 * .2 = $9. So in total, he paid 45 + 9 = $54.. The answer is: 54.

John decides to buy some birds. He got 50 dollars from each of his 4 grandparents. If each bird costs $20, how many wings did all the birds have? Give the rationale and then the answer.
Let's think step by step. He got 4 * 50 = $200. That means he was able to buy 200 / 20 = 10 birds. Since each bird has 2 wings he got 10 * 2 = 20 wings.. The answer is: 20.

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? Give the rationale and then the answer.
Let's think step by step. 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.. The answer is: 42.