Lizzy: Aria has twice as many high school credits as Emily, who has twice the number of high school credits as Spencer. If Emily has 20 credits, what's twice the total number of high school credits the three have?.
Me: Hmmm, let me think. I think this is the detailed solution:
If Emily has 20 credits, and Aria has 2 times as many, then Aria has 2 * 20 = 40 high school credits. Emily has twice the number of high school credits Spencer has, meaning Spencer has 20 / 2 = 10 high school credits. Altogether, the three have 40 + 20 + 10 = 70 high school credits. Twice the total number of high school credits the three have is 2 * 70 = 140. Final answer: 140.