Question: Emma has saved $230 in her bank account. She withdrew $60 to buy a new pair of shoes. The next week, she deposited twice as much money as she withdrew. How much is in her bank account now?
Answer: Emma had $230 - $60 = $170 left in her bank account after she withdrew $60. The next week, she deposited $60 x 2 = $120. Hence, she now has a total of $170 + $120 = $290 in her bank account. The answer is 290.

Question: Harrison Elementary School is overcrowded with 1590 students, so 40% of the students are going to move to a new school. There are 3 grade levels, and each grade level needs one 20-person advanced class and the rest of the students divided evenly into 6 additional classes. How many students will there be in each normal class at the new school?
Answer: First find how many students go to the new school: 1590 students * .4 = 636 students. Then divide that number by 3 to find how many students are at each grade level: 636 students / 3 grades = 212 students / grade. Then subtract the 20 students in the gifted class: 212 students - 20 students = 192 students. Then divide that number by 6 to find the number of students in each other class: 192 students / 6 classes = 32 students / class. The answer is 32.

Question: Peter has 20 books. He has read 40% of them. His brother has read 10% of them. How many more of these books has Peter read than his brother?
Answer: Peter has read 8 of these books because 20 x .4 = 8. His brother has read 2 of these books because 20 x .1 = 2. Peter has read 6 more books than his brother because 8 - 2 = 6. The answer is 6.

Question: Farmer Randy has 1700 acres of cotton he needs to have planted in 5 days. With a crew of 2 tractors working for 2 days and then a crew of 7 tractors working for another 3 days, how many acres of cotton per day does each tractor need to plant to meet their planting deadline?
Answer:
With 2 tractor teams working for 2 days, this is like 2 * 2 = 4 days worth of work by a single tractor, which they call tractor days. With 5 tractor teams working for 4 days, this is 7 * 3 = 21 tractor days. In total, the effort of all the tractor teams is 4 + 21 = 25 tractor days. If they need to plant 1700 acres with their 25 tractor days, then each tractor team needs to plant 1700 / 25 = 68 acres of cotton per day. The answer is 68.