Question

For all non - negative integers x and y, f(x,y) is defined as below.
f(0, y) = y + 1
f(x + 1, 0) = f(x, 1)
f(x + 1, y + 1) = f(x, f(x + 1, y)) find f(1, 2)?

• A. 2
• B. 4
• C. 3
• D. Cannot be determined

Answer 1

The correct option is B 4

f(1, 2) = f(0, f(1, 1));
Now f(1, 1) = f[0, f(1, 0)] = f[0, f(0, 1)] = f[0, 2] = 3
Hence, f(1, 2) = f(0, 3) = 4