1. When people cross the river with cats, chickens and rice, the boat can carry at least one of them, except rowing. When people are away, cats should eat chickens and chickens should eat rice. Try to design a safe ferry scheme and minimize the number of ferries.

Answer:

1 Take the chicken and come back empty-handed.

Bring back the cat and chicken.

Come back empty-handed with food.

Take the chicken there.

The perimeters of two rectangles A and B are equal. The aspect ratio of A is 3: 2, and that of B is 3: 5. What are the areas of A and B?

Answer:

A is 24 in length, 25 in width 16 in length 15 in width.

The area of A is 384, and the area of B is 375. The answer is not unique.

3. The ratio of copper to zinc in the alloy is 3: 2. Now add 6 grams of zinc to get 36 grams of zinc alloy. What is the ratio of copper to zinc in the new alloy?

Answer:

Copper and zinc are 1: 1.

A monkey picked 100 bananas in the forest and piled them up. The monkey's home is 50 meters away from the banana pile, and the monkey intends to carry the bananas home.

You can take up to 50 sticks at a time, but monkeys are greedy. He eats a banana every meter. Ask the monkey how many sticks he can take home at most.

Bananas?

25.

Recite 50 songs to 25 meters first. At this time, I ate 25 pieces and left 25 pieces. Put them down. Go back and recite the remaining 50. At 25 meters, I ate 25 more, and there are 25 more. Then, they picked up 25 cards and 50 cards on the ground and walked 25 meters home. Mr Yao, Mr P and Mr Q know that there are 16 cards in the desk drawer: A, Q, J, 8, 4, 2, 7, 3, K, Q and 5 of spades. Professor John chooses a card from 16 card, tells Mr. P the number of points in this card, and tells Mr. Q the color of this card. At this time, Professor John asked Mr. P and Mr. Q: Can you infer what this card is from the known points or colors? So, Mr. S heard the following conversation:

Mr. P: I don't know this card.

Mr q: I know you don't know this card.

Sir: Now I know this card.

Mr. Q: I know that, too.

After listening to the above conversation, Mr. S thought about it and correctly deduced what this card was.

Excuse me: What kind of card is this?

After eating 25, there are 25 left to go home.

1. How many parts can a plane be divided into by five straight lines at most?

When the sun sets on the hillside in the west, ducks croak into their nests. A quarter of the shore goes forward, half and half follow the wave; There are eight ducks behind me. How many ducks are there in my house?

3. There are 9 strains in line10, with 3 strains in each line. How to grow them?

4. Math riddle: ("/"is the fractional line)

The reciprocal of 3/4 is 7/8

1/ 100 1/2

Any power of 3.4 1

Play an idiom for each of the above.

5. After deleting the percent sign, the number is 0.4455 higher than the original number. What is the original number?

6. Party A, Party B and Party C each contribute 550,000 yuan to run a shop. 1/5 of Party A's total investment, and the rest shall be borne by Party B and Party C. Party B invests 20% more than Party C ... How much is the investment?

7. Fold the rope for three times and measure it, leaving 4m outside the well; The measuring rope is 40% folded, leaving 1 m outside the well. What is the depth of the well and rope?

8. A basket of apples was given to A, B and C .. A got 1/5 plus 5 apples, B got 1/4 plus 7 apples, C got half of the remaining apples, and the last one was 1/8 of a basket of apples. How many apples are there in this basket?

9. There are three workshops 180 people in a factory. The number of people in the second workshop is three times that in the first workshop, exceeding 1 person, and the number of people in the third workshop is half that in the first workshop, but less than 1 person. How many people are in each of the three workshops?

10, someone transported rice from place a to place b by car. Heavy trucks loaded with rice travel 50 kilometers a day, empty cars travel 70 kilometers a day, and make three trips back and forth on the 5 th. How many kilometers is it between A and B?

1 1, three years later, the two brothers are 26 years old, and the younger brother's age this year is exactly twice the age difference between the two brothers. Q: How old are the two brothers after three years?

Third groups

1 A monkey picked 100 bananas in the forest and piled them up. The monkey's home is 50 meters away from the banana pile, and the monkey intends to carry the bananas home.

You can take up to 50 sticks at a time, but monkeys are greedy. He eats a banana every meter. Ask the monkey how many sticks he can take home at most.

Bananas?

25.

Recite 50 songs to 25 meters first. At this time, I ate 25 pieces and left 25 pieces. Put them down. Go back and recite the remaining 50. How many parts can five straight lines divide the plane into at most?

When the sun sets on the hillside in the west, ducks croak into their nests. A quarter of the shore goes forward, half and half follow the wave; There are eight ducks behind me. How many ducks are there in my house?

4. There are 9 strains in line10, with 3 strains in each line. How to grow them?

5. Math riddle: ("/"is the fractional line)

The reciprocal of 3/4 is 7/8

1/ 100 1/2

Any power of 6.4 1

Play an idiom for each of the above.

7. After deleting the percent sign, the number is 0.4455 higher than the original number. What is the original number?

8. Party A, Party B and Party C each contribute 550,000 yuan to run a shop. 1/5 of Party A's total investment, and the rest shall be borne by Party B and Party C. Party B invests 20% more than Party C ... How much is the investment?

9. Fold the rope for three times and measure it, leaving 4m outside the well; The measuring rope is 40% folded, leaving 1 m outside the well. What is the depth of the well and rope?

10, a basket of apples is given to A, B and C. A gets 1/5 plus 5 apples, B gets 1/4 plus 7 apples, C gets half of the remaining apples, and the last one is 1/8 of a basket of apples. How many apples are there in this basket?

1 1. Three workshops in a factory 180 people. The number of people in the second workshop is three times that of the first workshop, exceeding 1, and the number of people in the third workshop is half that of the first workshop, but less than 1. How many people are in each of the three workshops?

12. Someone transported rice from place A to place B by car. Heavy trucks loaded with rice travel 50 kilometers a day, while empty trucks travel 70 kilometers a day, making three round trips on the 5th. How many kilometers is it between A and B?

13, three years later, the two brothers are 26 years old, and the younger brother's age this year is exactly twice the age difference between the two brothers. Q: How old are the two brothers after three years? At 25 meters, I ate 25 more, and there are 25 more. Then pick up 25 roots on the ground, 50 of them, and continue to walk home. A ***25 meters, you have to eat 25, and there are 25 left to get home.

14 Wrap a piece of paper on a piece of chalk, and then cut the chalk diagonally with a knife. What is the shape of the broken edge of the paper after unfolding?

Answer: sine curve