Step-by-step reasoning process: Let's say the river's length in the straight part of the river is x. The total length of the river is the length of the straight part plus 3 times the length of the straight part for the crooked part, which is x + 3x = 80. The total length of the river is 4x = 80. The straight part of the river is x = 80 / 4 = 20 miles.
The question and answer:
Question and answer: The length of the straight part of a river is three times shorter than the crooked part. If the river is 80 miles long, how long is the straight part of the river?
The answer is 20

Step-by-step reasoning process: Maria has 8 + 10 = 18 black pens. Maria has 8 + 7 = 15 blue pens. Maria has 8 + 18 + 15 = 41 pens in total.
The question and answer:
Question and answer: There are 8 red pens in Maria's desk drawer. There are 10 more black pens than red pens. There are also 7 more blue pens than red pens. How many pens are there in all?
The answer is 41

Step-by-step reasoning process: In the rooms with tall mirrors, Sarah saw her reflection a total of 10 reflections * 3 passes = 30 times. In the rooms with wide mirrors, Sarah saw her reflection a total of 5 reflections * 5 passes = 25 reflections. So Sarah saw her reflection a total of 30 + 25 = 55 times. In the rooms with tall mirrors, Ellie saw her reflection a total of 6 reflections * 3 passes = 18 times. In the rooms with wide mirrors, Ellie saw her reflection a total of 3 reflections * 5 passes = 15 times. So Ellie saw her reflection a total of 18 + 15 = 33 times. Therefore, Sarah and Ellie saw their reflections a total of 55 + 33 = 88 times.
The question and answer:
Question and answer:
Ellie went to visit a circus with Sarah and they both got lost in the house of mirrors. They have to travel through the house of mirrors a few times before they finally get out and when they leave, they discuss how many times they've seen their own reflections. Sarah says that every time they were in the room with tall mirrors, she saw her reflection 10 times and every time they were in the room with wide mirrors, she saw her reflection 5 times. Ellie says that every time they were in the room with tall mirrors, she saw her reflection 6 times and every time they were in the room with wide mirrors she saw her reflection 3 times. They both passed through the room with tall mirrors 3 times each and they both passed through the room with wide mirrors 5 times each. In total, how many times did Sarah and Ellie see their reflections?
The answer is 88