The answer should be 15 times 9 equals four
The function represents exponential growth (since the exponent is positive).
The percentage increase is, if I'm not mistaken, 181.3% (since 710 is just a constant, we don't need to worry about that - it won't affect the growth rate of the function)
2 tens, and 8 ones. I say this because 20 = 10 + 10 so, two tens. 8= 1+1+1+1+1+1+1+1 so, eight ones.
He worked a total of 405 minutes. Hope this helps!