A total of 12 x 10 = 120 bottles will be placed in 10 crates. Therefore, 130 - 120 = 10 bottles will not be placed in a crate.
The answer: 10
Reverse engineering the question: Joshua packs 12 bottles in each crate. He has a total of 130 bottles and 10 crates. How many bottles will not be placed in a crate?

On Monday Adam had 6 * 30 = 180 minutes of lessons, which is 3 hours. On Wednesday Adam spent twice as much time at school as on Tuesday, so he spent 2 * 3 = 6 hours at school. This means that during these three days Adam spent at school 3 + 3 + 6 = 12 hours.
The answer: 12
Reverse engineering the question: Adam goes to school every day. On Monday he had 6 lessons of 30 minutes each, and on Tuesday he had 3 lessons of 1 hour each. On Wednesday, Adam spent twice as much time at school as on Tuesday. How much time in total did Adam spend at school during these 3 days, in hours?

The chickens had 7 * 2 = 14 legs. The sheep had 5 * 4 = 20 legs. There were 14 + 20 = 34 legs.
The answer: 34
Reverse engineering the question: Farmer Brown fed 7 chickens and 5 sheep. How many total legs were there among the animals he fed?

Shells:80(.95) = 76. Opened Shells:76(.75) = 57.
The answer: 57
Reverse engineering the question:
A bag of pistachios has 80 pistachios in it. 95 percent have shells, and 75 percent of those have shells that are opened. How many pistachios in the bag have shells and have an opened shell?