James earns $10 per week as an allowance. After saving all his money for four weeks, he spends half of it on a new video game. He then spends a quarter of what is left to buy a new book. How much money does he have left?
He starts out with $10 * 4 = $<<10*4=40>>40.
James spend $40 / 2 = $<<40/2=20>>20 on the video game.
After buying the game, he has $40 - $20 = $<<40-20=20>>20 left.
He spent $20 / 4 = $<<20/4=5>>5 on the book.
He has $20 - $5 = $<<20-5=15>>15 left.
#### 15