Explanation : By definition, T(9) = Dist. From 9 to 100
As given, T(9) = 1+min (T(y), T()(z) = 1 + min (Dist.
from y to 100, Dist. From z to 100)
⇒ 1 = Dist. from 9 to y/Dist. From 9 to z
⇒ There are only two such values-one is the
simple one step on number line i.e. 10, and
the other is the shortcut associated with 9
i.e. 15.
⇒ Therefore, y and z are 10 and 15 (in any order)
⇒ Product yz = 150.