(21/2 + 31/5 )10
a =21/2 , b = 31/5
tr+1 = nCr a(n-r) br
for r = 0 we get 21/2 power 10 and the other term power 0 which is rational
now for further r values for the term to b rational
it shud be a multiple of 5 since we have 31/5
so we take r = 5
but r = 5 means first term is (

2)
5 which is irrational
so now r =10
i think there r the only two terms
hence sum =
(

2)
10 + 3
1/5 * 10 = 32 + 9 = 41
But pls correct me if wrong