I gotchu bro. First you want to expand 5 x 10^-6 which is (HINT: 10... and then move the decimal 6 to the LEFT) so: 0.000010 (you can drop the 0 after the 1)
So then, Take 0.04 and divide 0.00001 to get your answer.
(U got a test so im not gonna answer it for u. U got this)