Q: Melies bought 2 kg of meat. The meat costs $82 per kilogram. Melies has $180 in his wallet. How much money does he have left after paying for the meat?
A: Melies paid 2 x $82 = $164 for the 2 kg of meat. So he has $180 $164 = $16 left. The answer is 16.

Q: On a particular day, Rose's teacher read the register and realized there were twice as many girls as boys present on that day. The class has 250 students, and all the 140 girls were present. If all the absent students were boys, how many boys were absent that day?
A: If there were twice as many girls as boys present that day, then the number of boys is 140 girls / 2 girls / boy = 70 boys. The total number of students present that day is 140 girls + 70 boys = 210 students. If the class has 250 students, then the number of boys absent is 250 students - 210 students = 40 boys. The answer is 40.

Q: There are 92 students altogether. Twenty of them ride the school bus home together, 5/8 of the remaining ride their own bike home, and the rest whose houses are near the school walk home. How many students are walking home?
A:
If there are 92 students and 20 students take the bus home, the number of students who haven't taken the bus is 92 - 20 = 72 students. 5 / 8 of the students who didn't take the bus home ride bikes home, a total of 5 / 8 * 72 = 45 students. The number of students who neither took the bus nor biked home but walked home is 72 - 45 = 27. The answer is 27.