A king gets a crown made that costs $20,000. He tips the person 10%. How much did the king pay after the tip? Give the rationale and then the answer.
Let's think step by step. The tip was 20000 * .1 = $2000. So the total cost was 2000 + 20000 = $22000.. The answer is: 22000.

James gets a cable program. The first 100 channels cost $100 and the next 100 channels cost half that much. He splits it evenly with his roommate. How much did he pay? Give the rationale and then the answer.
Let's think step by step. The next 100 channels cost 100 / 2 = $50. So the total cost is 100 + 50 = $150. So he pays 150 / 2 = $75.. The answer is: 75.

Jack wants to send thank you cards to everyone who got him a gift for his wedding. He sent out 200 invitations. 90% of people RSVPed but only 80% of people who RSVPed actually showed up. Then 10 people who showed up didn't get a gift. How many thank you cards does he need? Give the rationale and then the answer.
Let's think step by step. He got 200 * .9 = 180 RSVP. Of those only 180 * .8 = 144 people showed up. So only 144 - 10 = 134 got him gifts and hence need thank you cards.. The answer is: 134.