One coloumb is 6.24 times ten to the eighteenth power amount of electrons in one second at one amp. Muliply that times five and then multiply that result times 600. That sure is a lot of electrons.
Do your own homework.
This comes down to how we define current.
A current of 1 ampere is said to flow when 1 coulomb of charge passes a given point in 1 sec.
Charge = Current * time
So, change the minutes to seconds and we have...
Charge = 5 * 10 * 60 = 3000 Coulombs
So the number of electrons must be..
3000 / (1.6 * 10^-19) = 1875 * 10^19 = 1.875 * 10^22 electrons.