+39 1. In what bases, b, does (b+10) divide into (8b+10) without any remainder?
2. Using each of the ten digits exactly once, find the two five-digit numbers that have the smallest product.
3. Given that a^2-b^2=150 and a-b=5, find the value of a+b
4. Find how many digits the base five number 5^(6^9) has when written in base five
