1. The problem statement, all variables and given/known data convert (352416)_7 to (...)_3 the _7 means base 7 and similarly, _3 means base 3. Idea : convert base 7 to base 10 then base 10 to base 3. I know I can use expansion, 3 * 7^6 + 5 * 7^6 ... to convert it to base 10. but in my exam, we are not allowed to use calculators, and I really not want to spend time on figuring out the power of X. So do you know a faster way to convert this to base 10? From then on I could convert it to base 3.