Question: Dexter filled 3 fewer plastic boxes with football cards than basketball cards. He filled 9 boxes with basketball cards and each box has 15 cards. For the boxes with football cards, he filled each box with 20 cards. How many cards does Dexter have in total?
Answer with step-by-step thinking: Dexter have 9 x 15 = 135 basketball cards. He filled 9 - 3 = 6 plastic boxes with football cards. So, he has 6 x 20 = 120 football cards. Therefore, Dexter has 135 + 120 = 255 cards in total.
So the answer is 255.

Question: Felicity and Adhira took separate trips. Felicity used 5 less gallons of gas than four times the number of gallons that Adhira used for her trip. Together the girls used 30 gallons of gas. How many gallons did Felicity use?
Answer with step-by-step thinking: Let A = Adhira's gallons. Felicity = 4A - 5. 5A - 5 = 30. 5A = 35. A = 7. Felicity used 23 gallons of gas for her trip.
So the answer is 23.

Question: Tonya is buying Christmas gifts for her sisters. She has 2 sisters and wants to spend the exact same amount on each. She buys her younger sister 4 dolls that cost $15 each. She plans to buy lego sets for her older sister. They cost $20 each. How many lego sets does she buy?
Answer with step-by-step thinking:
She spent $60 on her younger sister because 4 x 15 = 60. She buys 3 lego sets for her older sister because 60 / 20 = 3.
So the answer is 3.