Explain simply why 2 is the correct answer to: Alicia has to buy some books for the new school year. She buys 2 math books, 3 art books, and 6 science books, for a total of $30. If both the math and science books cost $3 each, what was the cost of each art book?. Explanation:
The total cost of maths books is 2 * 3 = 6 dollars. The total cost of science books is 6 * 3 = 18 dollars. The total cost for maths and science books is 6 + 18 = 24 dollars. The cost for art books is 30 - 24 = 6 dollars. Since he bought 3 art books, the cost for each art book will be 6 / 3 = 2 dollars.