Anumber is divided by 3 if the sum of the digits of the number is divisible by 3

Ben wants to play a carnival game that costs $2. in his pocket he has 5 red tickets worth 35 cents each, and 15 blue tickets worth 10 cents each. which of the following systems of inequalities correctly represents the constraints on the variables in this problem? let represent the red tickets and b represent the blue tickets.

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18

Find the sixth term of the following geometric sequence.