This question was a tricky question. I was so confused at the beginning.

So, I went to miss Burton and asked her how to do it and she showed me something that I would never even think about. She explained that usually you would do the equation on the inside and work your way out but, to make life easier, she said multiply both indexes which would be 6, and now to the question is so easy. Which # times itself = 64? 2!