Sophie does 4 loads of laundry a week and uses 1 dryer sheet per load. A box of dryer sheets costs $5.50 and has 104 dryer sheets in a box. On her birthday, she was given wool dryer balls to use instead of dryer sheets. How much money does she save in a year not buying dryer sheets?
Let's think: She does 4 loads of laundry a week and used 1 dryer sheet per load for a total of 4 * 1 = 4 dryer sheets in a week. She used 4 dryer sheets per week for 52 weeks for a total of 4 * 52 = 208 dryer sheets. Her box of dryer sheets has 104 sheets so she needs 208 / 104 = 2 boxes of dryer sheets. Each box costs $5.50 and she used 2 boxes so she now saves 5.50 * 2 = $11.00 by not buying dryer sheets.. The answer is: 11.

Roberto is raising chickens for eggs. He buys 4 chickens for $20 each. They cost $1 in total a week to feed and each produces 3 eggs a week that will last forever. He used to buy 1 dozen eggs a week and spent $2 per dozen. After how many weeks will the chickens be cheaper than buying his eggs?
Let's think: The chickens cost $80 because 4 x 20 = 80. His chickens produce a dozen eggs a week because 4 x 3 = 12. Each week that he has chickens is $1 cheaper than buying eggs because 2 - 1 = 1. After 80 weeks his chickens will be paid off because 80 / 1 = 80. After 81 weeks the chickens will be cheaper than buying eggs because 80 + 1 = 81.. The answer is: 81.

Isabella and Alexis went to the mall to buy some pants and dresses. Alexis bought 3 times more pants and dresses than Isabella. If Alexis bought 21 pairs of pants and 18 dresses, how many pairs of pants and dresses did Isabella buy in total?
Let's think: The number of pants Isabella bought is 21 / 3 = 7 pairs of pants. The number of dresses Isabella bought is 18 / 3 = 6 dresses. The total number of pants and dresses Isabella bought is 7 + 6 = 13.. The answer is: 13.

Valerie's cookie recipe makes 16 dozen cookies and calls for 4 pounds of butter. She only wants to make 4 dozen cookies for the weekend. How many pounds of butter will she need?
Let's think:
Her original recipe makes 16 dozen and she only needs 4 dozen so she needs to reduce the recipe by 16 / 4 = 4. For 4 dozen cookies, she needs to reduce her recipe by 4 and the original called for 4 pounds of butter so she now needs 4 / 4 = 1 pound of butter.. The answer is: 1.