A couple has two children. At least one of them is a boy. Assuming the probability of having a boy or girl is 50%, what is the probability that both children are boys?
If you answered 1/2, you’re not without comrades, but the generally accepted answer by statisticians (though not without debate) is 1/3. This is because there are four possible combinations: boy-boy, boy-girl, girl-boy and girl-girl. Since we are told one of the children is a boy (but we don’t know if it’s the first or second child), we can rule out the girl-girl combination, leaving three remaining options. Only one out of 3 is boy-boy, so we get a 1/3 chance.
1020. There are 6 men with 2 legs each, for a total of 12 legs. There are 36 cats with 4 legs each for a total of 144 legs. There are 216 kittens with 4 legs each for a total of 864 legs 12 + 144 + 864 = 1020.
I appear in the morning but am always there. You can never see me though I am everywhere. By night I am gone, though I sometimes never was. Nothing can defeat me but I am easily gone.
Fold the paper in half and make cuts that are almost entirely across the width of the paper. Switch between sides. When the paper is opened there will be a very large hole that you can climb through (carefully).
Jim and Wanda both have some apples. If Jim gives Wanda an apple, they will both have the same number of apples. However, if Wanda gives Jim an apple, Jim will have twice as many as Wanda. How many apples do Jim and Wanda each have?