An eccentric casino owner decides that his casino should only use chips in $4 and $7 denominations. Which of the following amount cannot be paid out using these chips?	Choose the correct choice from the following
A) $26	B) $29	C) $28	D) $25	E) $21
Yes, the number of 4 or/and 7 dollar chips can be zero, however both being zero mean that the casino is paying out $0, which is not realistic.   Each option but C can be represented as the sum of a multiple of 4 and a multiple of 7:   A. $29 = 7*3 + 4*2   B. $26 = 7*2 + 4*3   C. $25 = 7*3 + 4*1   E. $21 = 7*3   Answer: $28.
<result>C</result>
An eccentric casino owner decides that his casino should only use chips in $4 and $7 denominations. Which of the following amount cannot be paid out using these chips?