Question 1192417
 The combination formula is:

C(n, r) = n! / (r! * (n-r)!)

Where n is the total  r is the number we choose. 

 n = 26 (10 hearts and 10 diamonds) and r = 10. 

C(26, 10) = 26! / (10! * (26-10)!)
           = 10,400,600

10,400,600 ways to choose 10 hearts and 10 diamonds.