Can a mathematician assist?

explain how (2*10^-3)^3 = 8e^-9

i understand how the exponent is -9 but how does the 2 become an 8

If 10 men take 18 days to mow 60 acres of grass, how long will 15 men take to mow 80 acres?

Which expression is equivalent to the expression shown?

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.