There were 80 / 2 = 40 wireless mice sold. There were 80 / 4 = 20 optical mice sold. So, there were a total of 40 + 20 = 60 wireless and optical mice sold. Therefore, 80 - 60 = 20 trackball mice were sold this month.
The answer: 20
Reverse engineering the question: Marky owns a computer accessory shop. For this month, half of their sales are wireless mice, one-fourth are optical mice, and the rest are trackball mice. If Marky's shop was able to sell a total of 80 mice, how many of them are trackball mice?

If a cow drinks 80 liters of water in a day, it drinks 80 * 7 = 560 liters of water per week. Mr. Reyansh has 40 cows drinking 560 liters of water a week, totaling 560 * 40 = 22400 liters. In the ranch, a sheep drinks 1 / 4 * 80 = 20 liters of water in a day. The total amount of liters a sheep drinks in a week is 20 * 7 = 140 liters. Mr. Reyansh has ten times as many sheep as cows, that is 10 * 40 = 400 sheep. If each sheep drinks 140 liters of water in a week, 400 sheep drinks 400 * 140 = 56000 liters of water. Together, the cows and sheep drink 56000 + 22400 = 78400 liters of water per week.
The answer: 78400
Reverse engineering the question: Mr. Reyansh has a dairy farm with 40 cows. Each cow on the farm drinks 80 liters of water daily. He also has a sheep ranch with 10 times the number of cows, with each sheep drinking 1/4 times as much water as a cow does. How many liters of water does Mr. Reyansh use to water all of his animals in a week?

The second dose had a wait time of 20 / 2 = 10 minutes. So the total wait time is 20 + 10 = 30 minutes.
The answer: 30
Reverse engineering the question: John decides to get the vaccine for COVID. He has to wait 20 minutes for the first dose. The second dose has a wait time half as long. How long was the total wait time?

Micah picks 2 x 12 = 24 strawberries. After he eats 6, there are this many strawberries left for his mom: 24 - 6 = 18.
The answer: 18
Reverse engineering the question:
Micah picks 2 dozen strawberries from the field. He eats 6 and saves the rest for his mom. How many strawberries are there for his mom?