Hint Pascal TriangleSolutionIn the Pascals triangle it is co

Hint: Pascal Triangle!

Solution

In the Pascal\'s triangle, it is composed of terms C(n, r).

We it as

1
1 2 1
1 3 3 1
1 4 6 4 1

We see that the numbers keep increasing (as the pattern is adding up the previous terms).

Thus, the only one that produces C(n, r) = 2 is

n = 2, r = 1. There is no other pair of n and r. [ANSWER]