Reasoning and answer: 2 pounds of steak will cost Ken 2 * 7 = 14 dollars. Subtracting that amount from $20 will give 20 - 14 = 6 dollars. Ken will therefore get 6 dollars back.
The answer: 6
What was the question?
Question: At Ken's local store, a pound of steak is going for $7. He decides to get two pounds. At the till, he pays using a $20 bill. How much money will he get back?

Reasoning and answer: Let x represent the weight of the chihuahua. Pitbull:3x. Great dane:10 + 3(3x) = 10 + 9x. Total:x + 3x + 10 + 9x = 439. 13x + 10 = 439. 13x = 429. x = 33 pounds. Great dane:10 + 9(33) = 307 pounds.
The answer: 307
What was the question?
Question: A chihuahua, pitbull, and great dane weigh a combined weight of 439 pounds. The pitbull weighs 3 times as much as the chihuahua. The great dane weighs 10 more pounds than triple the pitbull. How much does the great dane weigh?

Reasoning and answer: Twenty shirts amount to $10 x 20 = $200. The cost of each pair of jeans is $10 x 2 = $20. So 10 pairs of jeans amount to $20 x 10 = $200. Therefore, the store will earn $200 + $200 = $400 if all shirts and jeans are sold.
The answer: 400
What was the question?
Question:
A clothing store sells 20 shirts and 10 pairs of jeans. A shirt costs $10 each and a pair of jeans costs twice as much. How much will the clothing store earn if all shirts and jeans are sold?