Lizzy: John has 3 children. He and his wife are supposed to buy notebooks for their sons but they couldn't agree on how many to buy. So John bought 2 notebooks for each of his children and John's wife bought 5 notebooks for each of them. How many notebooks did they buy in total for their children?.
Me: Hmmm, let me think. I think this is the detailed solution:
John bought 2 notebooks for his 3 children: 2 notebooks / child x 3 children = 6 notebooks. The father bought 6 notebooks. John's wife bought 5 notebooks for their three children: 5 notebooks / child x 3 children = 15 notebooks. The mother bought 15 notebooks. Now, the total number of notebooks is 6 notebooks + 15 notebooks = 21 notebooks. Final answer: 21.