Coin Exchange Problem

#1

plz explain the question wrt to the test case

#2

hello @akb.tech17
You can change 12 into 6, 4 and 3, and then change these into $6+$4+$3 = $13.
basically in this problem you can exchange-> f(n) -> max(n, f(n/2) +f(n/3)+f(n/4) ) (take floor value if not divisible)