Question: Julian has 400 legos and wants to make lego models of two identical airplanes. If each airplane model requires 240 legos, how many more legos does Julian need?
Answer: Two aeroplanes require 240 legos / airplane x 2 airplanes = 480 legos. Julian needs 480 legos - 400 legos = 80 more legos. The answer is 80.

Question: After evaluating his students on the final exams. Professor Oscar reviews all 10 questions on each exam. How many questions must he review if he has 5 classes with 35 students each?
Answer: For each class, he has to review the questions of 35 students, in total, he will review 10 * 35 = 350 questions. For the 5 classes, he will review a total of 350 * 5 = 1750 questions. The answer is 1750.

Question: During the Christmas holidays, all shops are closed for 3 days. During each day during this time, a shop called "Surprise" could have earned 5 thousand dollars. How much potential revenue did the "Surprise" shop lose during 6 years of activity?
Answer: In one day the shop is losing 5 thousand dollars, so during three days, the losses are 5 * 3 = $15,000. Christmas holidays are once a year, so in 6 years the shop "Surprise" could have earned another $15,000 * 6 = $90,000. The answer is 90000.

Question: John climbs up 9 flights of stairs. Each flight is 10 feet. If each step is 18 inches, how many steps does he climb up?
Answer:
He has to climb 9 * 10 = 90 feet. That means he needs to climb 90 * 12 = 1080 inches. That means he needs to climb 1080 / 18 = 60 stairs. The answer is 60.