David is throwing Robert a surprise birthday party but he has to stay within his budget. He spent half of his money plus $2.00 on the cake. Half of what he had left plus $2.00 was spent on balloons and streamers. Then he spent half of what he had left plus $1.00 on candy. Now he is out of money, how much did he start with?
This one is best solved working backwards, the last part David spent half of what was left plus $1.00 on candy and then was out of money. That means he must have spent $2.00 on Candy as $1.00 was half of what he had using the same logic backwards: $2.00 on candy $6.00 on Balloons and Streamers $12.00 on the cake Total of $20.00.
Hai con chó đang lang thang ở công viên. Con chó trắng tên Đen, con chó đen tên Trắng. Nam thấy chúng dễ thương, liền thẩy trái banh ra xa rồi ra lệnh “Đen, đi lượm trái banh”… Đố bạn con chó nào sẽ đi lượm?