A band's members each earn $20 per gig. If there are 4 members and they've earned $400, how many gigs have they played? Give the rationale and then the answer.
Let's think step by step. The band earns $80 per gig because 4 x 20 = 80. They played 5 gigs because 400 / 80 = 5.. The answer is: 5.

The Zargon Destroyer spacecraft can travel at 2 billion miles per hour in normal space, but when moving through a black hole they travel three times faster. If the Zargon Destroyer is making a voyage that travels seven hours in normal space and two hours through a black hole, how many billions of miles would they have traveled? Give the rationale and then the answer.
Let's think step by step. A spacecraft flying through normal space for seven hours at 2 - billion miles per hour travels 7 * 2 = 14 billion miles. A spacecraft flying through a black hole at 3 * 2 = 6 billion miles per hour. Thus, a spacecraft flying through a black hole for two hours travels 2 * 6 = 12 billion miles. Therefore, in total, the Zargon spacecraft will travel 14 + 12 = 26 billion miles.. The answer is: 26.

There are 40 students in a class. If 1/10 are absent, 3/4 of the students who are present are in the classroom, and the rest are in the canteen, how many students are in the canteen? Give the rationale and then the answer.
Let's think step by step. Out of the 40, 40 x 1 / 10 = 4 students are absent. So, 40 - 4 = 36 students are present in school. Out of the 36, 36 x 3 / 4 = 27 students are in the classroom. This means, 36 - 27 = 9 students are in the canteen.. The answer is: 9.