Sir/madam, 
I wish to apply to join your staff as an office assistant. I am miss Oti Immaculater Uchenna, from Aboh Mbaise L.G.A in Imo state, resident of portharcourt. 
I am an articulate, hardworking and resourceful individual and I believe I'll do a great job in said position. I am a graduate of Rivers state polytechnic,  where I studied Estate management and I'm computer literate.  You will find more details about me attached with this cover letter. Hopefully  I will get an opportunity to interview with you. 
Thank you for your time and consideration.  
Sincerely yours 
Oti I. Uchenna