Come up with a question and reasoning that would justify [2] as the answer.
The question is: Viggo spent $80 on a shirt. He paid the shirt using $20 and $10 bills. If she gave the clerk one more $20 bill than $10 bills, how many $10 bills did he give?
Reasoning: Let x be the number of $10 bills. So, there are (x + 1) $20 bills. Adding the $10 and $20 bills should sum up to $80 so the equation is 10x + 20(x + 1) = 80. Then, distribute 20 to x + 1 so it becomes 10x + 20x + 20 = 80. Combining the like terms on the left side gives 30x + 20 = 80. Then transfer 20 to the right side of the equation, so it becomes 30x = 60. To solve for x, we have 60 / 30 = 2. Therefore, there are 2 $10 bills.

Come up with a question and reasoning that would justify [120] as the answer.
The question is: Fred has 12 identical candy bars, and Uncle Bob has 6 more. If Jacqueline has ten times the total number of candy bars Fred and Uncle Bob have, what's 40% of Jacqueline's candy bars?
Reasoning: If Fred has 12 identical candy bars, uncle Bob has 12 + 6 = 18 candy bars. Together, Fred and Uncle Bob have 12 + 18 = 30 candy bars. Jacqueline has ten times the total number of candy bars Fred and Uncle Bob have, meaning she has 10 * 30 = 300 candy bars. 40% of Jacqueline's candy bars is 40 / 100 * 300 = 120.

Come up with a question and reasoning that would justify [60] as the answer.
The question is: Jason is mixing a batch of black paint. He needs to add 2 grams of charcoal for every 30 ml of water. If he adds 900 ml of water, how much charcoal does he add?
Reasoning: First find how many ml of water Jason needs for 1 gram of charcoal: 30 ml / 2 grams = 15 ml / g. Then divide the amount of water Jason uses by the amount of water per gram of charcoal to find how much charcoal he uses: 900 ml / 15 ml / g = 60 g.