Here are all those you posted:
how many times larger is 7 x 10^8 than 1 x 10^7?
Divide the first by the second:
how many times larger is 4 x 10^8 than 2 x 10^5?
Divide the first by the second:
how many times larger is 1 x 10^1 than 5 x 10^8?
It's not larger! It's smaller! Maybe you meant
how many times larger is 5 x 10^8 than 1 x 10^1?
Divide the first by the second:
how many times is larger 3 x 10^5 than 1 x 10^4?
Divide the first by the second:
Edwin