What is 5x10^-7 as a decimal

Abee with velocity vector r'(t) starts out at (5, −5, −3) at t = 0 and flies around for 5 seconds. where is the bee located at time t = 5 if 5 0 r'(u)du = 0?

The cash price of a television is $580.the hire-purchase price of the television is $865.the hire-purchase price is an initial deposit of n% of the cash price and 6 equal monthly payments of $120.find the value of n.

Which one ? is the answer and how to find this answer