The Age of Adam and Eve and the Age of the Earth
Hopefully by now you've realised that the correct answer is that they would be ONE year old one year after God made them. (The question said to assume that they were the equivalent of 20 when God made them.) Their apparent age to those who refused to believe the miraculous account of their creation would be 21 - but their actual age would be 1. If a scientist were able to go back in time and measure their height, weight, bone density etc they'd conclude that they were mature adults somewhere around 21 years of age. But they would never be able to get the correct answer of their actual age (1 year old) unless they accepted the word of Adam and Eve as to what actually happened - and they could not do that unless they accepted that the biblical God exists.
Now apply the same test to the trees - 1 second after God made the trees they would be 1 second old but they'd look like they were mature trees that were decades old. They may even have had growth rings as this may have been necessary for the strength of the trees.
1 second after God made the rocks on earth they'd be 1 second old - but if a scientist were able to go back in time and test their ages he'd think they were thousands or even millions of years old due to the uniformitarian assumptions that are involved in radiometric dating. (See Radioactive "Dating" Failure - Answers in Genesis - Recent New Zealand Lava Flows Yield “Ages” of Millions of Years.)
At the end of the creation week all of the stars would have been fully shining. Again - if secular scientists could go back in time to moments after God made the stars they'd think the stars were millions or billions of years old - but they'd be wrong because God miraculously made a mature creation where the stars were fully shining by the end of the creation week. This may have been done by God making the speed of light massively faster than it is today during the 4th and 5th days of creation. This would not violate the laws of physics because those laws would not have been finalised until later in the creation week. (It's also worth pointing out that modern secular scientists believe in a much faster than light expansion of the early universe.)
I'm sure by now you get the point. If God made a mature and fully functioning universe in 6 literal days how can secular scientists EVER get the right answer if they a priori rule out the possibility of a miraculous creation and a young earth? If you think about it you'll realise that if God really did create a mature universe it is impossible to get the right conclusion until you change your starting presupposition from an atheistic one to a biblical one and accept God's version of the account of creation.
This is not deceptive of God because he told us in the Bible that he took 6 days to make everything, not vast aeons or billions of years. It's deceptive of the scientists and media who present billions of years and evolution as if it were a fact. If scientists refuse to accept the eye-witness account of the God who was there and made it all, then they will never be able to know the truth about how everything began.
Now apply the same test to the trees - 1 second after God made the trees they would be 1 second old but they'd look like they were mature trees that were decades old. They may even have had growth rings as this may have been necessary for the strength of the trees.
1 second after God made the rocks on earth they'd be 1 second old - but if a scientist were able to go back in time and test their ages he'd think they were thousands or even millions of years old due to the uniformitarian assumptions that are involved in radiometric dating. (See Radioactive "Dating" Failure - Answers in Genesis - Recent New Zealand Lava Flows Yield “Ages” of Millions of Years.)
At the end of the creation week all of the stars would have been fully shining. Again - if secular scientists could go back in time to moments after God made the stars they'd think the stars were millions or billions of years old - but they'd be wrong because God miraculously made a mature creation where the stars were fully shining by the end of the creation week. This may have been done by God making the speed of light massively faster than it is today during the 4th and 5th days of creation. This would not violate the laws of physics because those laws would not have been finalised until later in the creation week. (It's also worth pointing out that modern secular scientists believe in a much faster than light expansion of the early universe.)
I'm sure by now you get the point. If God made a mature and fully functioning universe in 6 literal days how can secular scientists EVER get the right answer if they a priori rule out the possibility of a miraculous creation and a young earth? If you think about it you'll realise that if God really did create a mature universe it is impossible to get the right conclusion until you change your starting presupposition from an atheistic one to a biblical one and accept God's version of the account of creation.
This is not deceptive of God because he told us in the Bible that he took 6 days to make everything, not vast aeons or billions of years. It's deceptive of the scientists and media who present billions of years and evolution as if it were a fact. If scientists refuse to accept the eye-witness account of the God who was there and made it all, then they will never be able to know the truth about how everything began.
Many people, including Christians don't understand why Genesis is relevant to whether or not the Bible is true.
Why Genesis and the Creation vs Evolution Issue is so Important
Why Genesis and the Creation vs Evolution Issue is so Important
The above castle diagrams illustrate the culture war that is going on today between the Church and secular culture. Statistics show that 2/3 of the young people in our churches are leaving church when they leave their teen years. One of the biggest reasons for this is that they are not being discipled to have a strong biblical worldview that has real answers for the skeptical questions of the age. The church by in large has neglected apologetics, and the results have been catastrophic. For more on this issue see the videos below, and also the Answers in Genesis books "Already Gone", "Already Compromised", and "The Lie: Evolution".
"Ken Ham's Foundations: Relevance of Genesis"
Bill Nye "The Science Guy" debated Ken Ham in this highly important debate.
Bill Nye Debates Ken Ham
If you have any specific questions or objections to the issues raised here then you can contact me, but I encourage you to check out the Answers in Genesis website, and the Creation Ministries International creation.com website. Both websites have thousands of articles on the creation vs evolution topic.