Which amount of postage can be formed using just 4-cent and 11-cent stamps?
🎥 Video solution / Text Solution of this question is given below:
Postage combinations possible = $4x + 11y$.
The smallest value not possible is given by Frobenius number $= ab - a - b = 4\times11 - 4 - 11 = 29$.
Hence, every amount $\ge 30$ can be formed.