Apologize for lengthiness.... NB: edited only slightly changing spelling errors and some erroneously lacking text ;2017-May-15th,23:45: changes in BOLD-ITALIC)

Mustafa, I know these chemical calculations always seem to be tricky....and they trick us...(since many of us aren't promovated chemists at all (;-)):

first of all:  preparing small volumes of "more/less concentrated solutions" might be tricky....so  if you read of   "take 1 ml, or even 10 ml"  think about making at least the double volume or the 10fold volume....only because it might be easier to handle and to mix and to dispense then the necessary volumes..

secondly: if you mix 2 solutions (each of them in same volume v1 and v2 but with different ions or chemical components each) together, you have to calculate their diluting themselves 1:1 (so, mixing of 10 ml 5M A  with 10ml of 5 M B = solution containing 2.5M A and 2.5M B).  You'll find (if you search in the web or read handbooks of clinical or physiological and/or biological Chemistry) also related mixing / calculating formulas.

In your special case now, following my points 1 & 2):

Natrium(sodium)Chloride NaCl (ex wikipedia):

NaCl                                     molar mass =  58,44 g·mol−1 

1M=                    58,44g/L

2.5M=              146.1g/L

5.0M=              292,2g/L

for 10ml of 2.5 M:  1,46 g,                 [for 20ml of 2.5 M:  2,92 g] but you need only 

10 ml 5.0M,   so prepare

Double Concentration:  2,92g NaCl/10ml (= literally: „in 10 ml a. bidest.“), perhaps better  20ml double concentration(=5.0M):  5,84g NaCl /20 ml (= literally: „in 20 ml aqua dest or bidest.“)

 ---------------

Tri-sodiumcitrate C6H5Na3O7          (ex wikipedia):

C6H5Na3O7                                       molar mass = 258,07 g·mol−1

1M=      258,07g/L

2.5M=   645,175g/L          =  :(/)100=    6,45175g/10 ml   or   12,9035g/20 ml    (or 64,5175g/100ml)

5.0M= 1290,35g/L           = :(/)100=    12,9035g/10ml      or   25,80,7g/20 ml 

Let dissolve under constant stirring thouroughly all / each components absolutely 100% = completely.

Finish: 

Pour together:

10 ml of 5.0M NaCl-solution  and

10ml of 5.0M Trisodiumcitrate solution.

Best wishes and regards, WM

NB: edited only slightly changing spelling errors and some erroneously lacking text ;2017-May-15th,23:45: changes in BOLD-ITALIC)

Really good basic and informative instructions you might find (only as one example):   https://www.training.nih.gov/assets/Lab_Math_II_Transcript_-_508.pdf

 Vielen lieben Dank Prof. Wolfgang :) 

Simply, you can mix 10 ml of 5.0 M of each component.

Dear Mustafa Gharib, you're welcome!

I am sorry for the lengthiness of my reply... not knowing where the problem of understanding really was...(or did you only want to test me??)(:-) anyway: pleas don't entitle me "Professor" ....I am not...only the son of a 97 years old former, retired professor....who always was a teacher and professor her whole life:  my mother.....

God bless you and yours too, Regards, Wolfgang.

Perhaps this would help you more to understand chemical preparations

http://faculty.tamucc.edu/plarkin/4101folder/CHEM%204401%20L1%20Units.pdf

http://www.srmuniv.ac.in/sites/default/files/files/FULL%20RECORD.pdf

http://homepages.gac.edu/~cellab/appds/appd-j.html

Dear Mrs / Dr. / Prof. Eman El-Abd, your contribution is thankfully acknowledged..., I am collecting such documents....Regards, WM