Answer the following question.
Ruby is taking dance lessons. They cost $75 for 10 classes in one pack. She can add additional classes at the price of 1/3 more than the average price of a class on the lesson in the pack. if she takes 13 total classes, how much does she pay?
Step-by-step reasoning process: The classes in the pack cost $7.5 each because 75 / 10 = 7.5. An additional class costs $10 because 7.5 x (1 + (1 / 3)) = 10. She buys 3 extra classes because 13 - 10 = 3. Her three additional classes cost $30 because 3 x 10 = 30. Her total cost is $105 because 75 + 30 = 105.
The answer is 105.

Answer the following question.
Pete has a bag with 10 marbles. 40% are blue and the rest are red. His friend will trade him two blue marbles for every red one. If Pete keeps 1 red marble, how many total marbles does he have after trading with his friend?
Step-by-step reasoning process: He starts with 4 blue marbles because 10 x .4 = 4. 60% of the marbles are red because 100 - 40 = 60. He has 6 red marbles because 10 x .6 = 6. He trades 5 red marbles because 6 - 1 = 5. He gets 10 blue marbles because 5 x 2 = 10. He has 15 marbles now because 4 + 1 + 10 = 15.
The answer is 15.

Answer the following question.
Julia has $40. She spends half of her money to buy a new game for her phone. She spends a quarter of what she has left on in-game purchases. How much money does she have left?
Step-by-step reasoning process: Julia spend $40 / 2 = $20 on the game. After buying the game, she has $40 - $20 = $20 left. She spent $20 / 4 = $5 on in - game purchases. She has $20 - $5 = $15 left.
The answer is 15.

Answer the following question.
Austin bought his seven friends each a robot. Each robot costs $8.75. He was charged $7.22 total for tax. He left with $11.53 in change. How much did Austin start with?
Step-by-step reasoning process: First we need to find the total amount for the robots. 7 robots * $8.75 per robot = $61.25 in total. Now we need to add in the tax $61.25 for the robots + $7.22 for tax = $68.47 total spent in store. Now to find what was the beginning amount we take the $68.47 total spent in - store + $11.53 in change = $80 to start.
The answer is 80.