Question: Mrs. Watson is grading 120 final exams from her American History class. On Monday, she grades 60% of the exams. On Tuesday, she grades 75% of the remaining exams. On Wednesday, how many more exams does she need to grade?
Answer with step-by-step thinking: On Monday, Mrs. Watson grades 120 x 60% = 72 final exams. At the end of Monday, she has 120 - 72 = 48 exams left to grade. On Tuesday, she grades 48 x 75% = 36 final exams. On Wednesday, she has 48 - 36 = 12 exams left to grade.
So the answer is 12.


Question: Silvia wants to buy a new guitar online. The price of the guitar has a suggested retail price of $1000. Guitar Center has a special deal of 15% off but has a shipping fee of $100. Sweetwater has a 10% off deal with free shipping. How much will she save by buying from the cheaper store compared to the other store?
Answer with step-by-step thinking: The discount saved when buying from Guitar Center would be $1000 * 15% = $150. The total cost when buying from Guitar Center would be $1000 - $150 discount + $100 shipping = $950. The discount when buying from Sweetwater would be $1000 * 10% = $100. The total cost when buying from Sweetwater would be $1000 - $100 discount + $0 shipping = $900. Thus, Silvia would save $950 - $900 = $50 when buying from Sweetwater.
So the answer is 50.


Question: Holly wants to plant a wall of privacy trees along her fence line. Her fence is 25 yards long. At maturity, the trees she wants to plant will measure 1.5 feet wide. Right now, these trees are on sale for $8.00 apiece. How much will it cost her to plant a row of the trees to run the length of her fence?
Answer with step-by-step thinking:
3 feet are in 1 yard and her fence is 25 yards long so her fence is 3 * 25 = 75 feet long. At maturity these trees will measure 1.5 feet and she needs them to run along her 75 - foot fence so she needs 75 / 1.5 = 50 trees. The trees cost $8.00 apiece and she needs 50 so 8 * 50 = $400.00 worth of trees.
So the answer is 400.