GOOD BRAIN TEASERS MATH BRAIN TEASERS

1) If it takes twenty minutes to hard-boil one goose egg, how long will it take to hard-boil four goose eggs? e

20 minutes, 4 eggs can be boiled at the same time.

2) Is there a 4th of July in England? Yes or No?

….Yes. It comes right after the 3rd.

3) Some months have 31 days. How many have 28?

…..Twelve (12). All of them have at least 28 days.

4) Can a man in California marry his widow’s sister?

….No. He must be dead if it is his widow.

5) Take the number 30, divide it by 1/2, and then add 10.

What do you get?

….. Seventy (70). Thirty (30) divided by 1/2 is 6.

6) A doctor gives you three pills and tells you to take one every half

an hour. How long will the pills last?

……One hour. If you take the first pill at 1:00, the second at

1:30, and the third at 2:00, the pills have run out and only one hour

has passed.

7) A farmer has 17 sheep. All but 9 of them die. How many sheep are

left?

….. Nine (9). Like I said, all BUT nine die.

8) How many animals of each species did Moses have on the ark?

…… None. I didn’t know that Moses had an ark.

9) A butcher in the market is 5′ 10 tall. What does he weigh?

….. Meat … that is self-explanatory.

MORE BRAIN TEASERS

1) A big fat Indian and a small thin Indian were sitting outside a teepee, each smoking a pipe. The little Indian was the son of the big Indian, but the big Indian was not the little Indian’s father. How come?

{Solution}

The big Indian was the little Indian’s mother.

2) Mary’s husband’s father-in-law is Mary’s husband’s brother’s brother-in-law, and Mary’s sister-in-law is Mary’s brother’s stepmother. How did this happen?

{Solution}

Mary’s father married the sister of Mary’s husband.

3) Over the side of a boat floating in a harbor there hangs a rope ladder containing ten rungs. Each rung is one foot from the next one and the bottom rung is resting on the surface of the water. The tide rises at a rate of one foot an hour. How long will it take the water to reach the top rung?

{Solution}

It will never reach the top rung because the boat will rise with the tide.

4) A sparrow has fallen into a hole in a rock. The hole measures three inches in diameter and is three feet deep. Due to the depth of the hole, the sparrow cannot be reached by hand. We cannot use sticks or canes, because we could hurt the bird. How can you get the bird out?

{Solution}

By gradually pouring sand into the hole. The bird will keep moving so that it is not buried in the sand, forcing it higher until it comes out.

5) Timothy and Urban play a game with two dice. But they do not use the numbers. Some of the faces are painted red and the others blue.

Each player throws the dice in turn. Timothy wins when the two top faces are the same color. Urban wins when the colors are different. Their chances are even.

The first die has 5 red faces and 1 blue face. How many red and how many blue are there on the second die?

{Solution}

Each die has 6 faces. When two dice are thrown, there are 36 equally possible results. For chances to be even, there must be 18 ways of getting the same color on top. Let X be the number of red faces on the second die. We have: 18 = 5X + 1(6 – X)

X = 3

The second die must have 3 red faces and 3 blue faces.

A ribbon is 30 inches long. If you cut it with a pair of scissors into one-inch pieces, how many snips would it take?

{Solution}

Twenty-nine snips. The last two inches are divided by one snip.

A Ferrari is traveling at 30 miles per hour on a head-on collision course with a Maserati, which is being driven at a leisurely 20 miles per hour. When the two cars are exactly 50 miles apart, a very fast fly leaves the front fender of the Ferrari and travels towards the Maserati at 100 miles per hour. When it reaches the Maserati, it instantly reverses direction and flies back to the Ferrari and continues winging back and forth between the rapidly approaching cars. At the moment the two cars collide, what is the total distance the fly has covered?

{Solution}

At first glance it may seem that a horrendous calculation is necessary to solve this: the sum of an infinite series of numbers that get smaller and smaller as the cars approach each other. But if you focus on time rather than distance, a solution is easy. The cars are 50 miles apart and traveling towards each other at a combined speed of 50 miles per hour, so they will meet in one hour. In that hour, a fly that flies at 100 miles per hour will naturally travel 100 miles.

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