find the value of `10_(C_7)`

If .^(20)C_(r+1)=.^(20)C_(r-1) then find the value of .^(10)C_(r) .

If ^(10)C_(x)=^(10)C_(x+4), find the value of x

|(.^10C_4,.^10C_5,.^11C_m),(.^11C_6,.^11C_7, .^12C_(m+2)),(.^12C_8,.^12C_9,.^13C_(m+4))|=0 then find the value of m

find the value of   7_(C_2)