We have a question: A marathon is 26 miles. He can run the first 10 miles in 1 hour. For the remaining miles he runs at 80% that pace. How long does the race take?
And an answer: 3
So how you got the answer?
There are 26 - 10 = 16 miles left for the rest of the race. He runs 10 * .8 = 8 miles per hour. So it takes him 16 / 8 = 2 hours. So in total it takes 1 + 2 = 3 hours.

We have a question: Jon’s textbooks weigh three times as much as Brandon’s textbooks. Jon has four textbooks that weigh two, eight, five and nine pounds respectively. How much do Brandon’s textbooks weigh?
And an answer: 8
So how you got the answer?
Jon’s textbooks weigh 2 + 8 + 5 + 9 = 24 pounds. Thus, Brandon’s textbooks weigh 24 / 3 = 8 pounds.

We have a question: An 18-month magazine subscription is normally $34. The magazine is currently running a promotion for $0.25 off each twice-a-month issue when signing up for the 18-month subscription. How many dollars cheaper is the promotional subscription than the normal one?
And an answer: 9
So how you got the answer?
The subscription sends twice monthly issues, so there are 2 * 18 = 36 issues. Thus, the promotional offer is 36 * 0.25 = $9 cheaper than the normal subscription.