We have a question: Yvonne and Janna were writing their 1000-word pair research paper. Yvonne was able to write 400 words while Janna wrote 150 more words than Yvonne. When they edited their paper, they removed 20 words and added twice as many words as they removed. How many more words should they add to reach the research paper requirement?
And an answer: 30
So how you got the answer?
Janna wrote 400 + 150 = 550 words. Together, they wrote 400 + 550 = 950 words. They have 950 - 20 = 930 words left after omitting 20 words. Then 20 x 2 = 40 words were added during the editing. Overall, they have 930 + 40 = 970 words. Thus, they should add 1000 - 970 = 30 more words.

We have a question: Brenda bakes 20 cakes a day. She does this for 9 days and then sells half of the cakes. How many cakes are left with Brenda?
And an answer: 90
So how you got the answer?
After 9 days, Brenda bakes 20 * 9 = 180 cakes. After she sells half of them, the remaining will be 180 / 2 = 90 cakes.

We have a question: Gary manages two Amazon distribution centers. The first center processes 10000 packages per day, and the second center processes three times that volume. If Amazon makes 5 cents of profit per package, how much profit per week do the two centers make combined?
And an answer: 14000
So how you got the answer?
First find how many packages the second center processes per day: 10000 packages / day * 3 = 30000 packages / day. Then add the packages the first center processes: 30000 packages / day + 10000 packages / day = 40000 packages / day. Then multiply the number of packages by Amazon's profit per package to find Amazon's daily profit: 40000 packages / day * $0.05 / package = $2000 / day. Then multiply the daily profits by the number of days in a week to find the weekly profits: $2000 / day * 7 days / week = $14000 / week.