The ball can't be 10 cents, because 10 cent ball + 1.10 dollar bat = 1.20, and it'd exceed the total. Since the difference is 1 dollar, we can do ball + ball +

The ball can't be 10 cents, because 10 cent ball + 1.10 dollar bat = 1.20, and it'd exceed the total. Since the difference is 1 dollar, we can do ball + ball + 1 dollar = 1.10, then we can see that 2(ball) = 10 cents, so 10/2 = 5 cents for the ball. I think the questions gage whether or not the person's beliefs/thoughts/rightness come intuitively and they decide to settle, or they keep searching.