SOLUTION: C(10,r)=120

The simplest way to solve this equation is to find in the Internet the 11-th row of the Pascal's triangle.


I found it at this link

http://jwilson.coe.uga.edu/EMAT6680Su12/Berryman/6690/BerrymanK-Pascals/BerrymanK-Pascals.html



and found the value of  r= 3  in this way.


The last step is to check this solution:   =  = 10*3*4 = 120.              ! Correct !