We have a question: Oliver has 4 friends that he is inviting to a party at the arcade. Game tokens cost 30 for $1. Each game costs 2 tokens. If he wants all his friends to get to play 60 games each, how much will it cost?
And an answer: 16
So how you got the answer?
He needs to buy enough tokens for 240 games because 4 x 60 = 240. He needs to buy 480 tokens because 2 x 240 = 480. He needs to spend 160 because 480 / 30 = 16.

We have a question: Jesse is desperately trying to finish a book for a school book report due on Monday so he can play this weekend. Friday afternoon, he read the first 5 chapters, which were 10, 15, 27, 12, and 19 pages, respectively, before taking a break. To his dismay, he found that he was only 1/3 of the way through the book. How many pages does he still have to read?
And an answer: 166
So how you got the answer?
So far, Jesse has read 10 + 15 + 27 + 12 + 19 = 83 pages. That's 1 / 3 of the book, so the remainder of the book is twice as many pages, or 2 * 83 = 166 pages.

We have a question: A bar of steel weighs twice the mass of a bar of tin. If a steel bar also weighs 20 kgs more than a copper bar and a copper bar weighs 90 kgs, calculate the total weight of a container with 20 bars of each type of metal.
And an answer: 5100
So how you got the answer?
The total weight of 20 bars of copper is 20 * 90 = 1800kgs. If a copper bar weighs 90 kgs, and a steel bar weighs 20 kgs more than a copper bar, the weight of a steel bar is 90 + 20 = 110 kgs. If a bar of steel weighs 110 kgs, 20 bars will weigh 20 * 110 = 2200kgs. The total weight of 20 bars of copper and steel is 2200 + 1800 = 4000 kgs. A bar of steel weighs twice the mass of a bar of tin, meaning a bar of tin weighs 110 / 2 = 55 kgs. The total weight of 20 bars of tins is 55 * 20 = 1100 kgs. The total weight of 20 bars of each metal is 4000 + 1100 = 5100 kgs.