[ [ equations in integers ]

A cashier has only 72-ruble bills, and you have only 105-ruble bills (both in unlimited quantities).

a) Will you be able to pay the cashier one ruble?

b) And 3 rubles

#
a) Since both 72 and 105 are multiples of 3, the amount paid can only be a multiple of 3.

b) For example, you give the cashier 11 bills, and he gives you 16 bills in return.

## Answer

a) You will not be able to