The answer is A.Use a compound interest calculator. Multiple sites to use. For me, I had to use my head for a while
For company a it would be at the 8th hour and they would be 210 and for company b it would be at the 7th hour
If its just 5.35 then no. But if its a number like pie then yes.
1/10 in fraction from or 0.1 in decimal form