Elementary school math problems for detailed explanations, thank you!

1. The original price of movie tickets is a few yuan, and now each ticket is sold at a price of 3 yuan, the audience has increased by half, and the income has increased by 1 5, how much is the original price of a movie ticket?

Answer] The current price is equivalent to (1 1 5) (1 1 2) 4 5 of the original price, so the original price is 3 (1 4 5) 15 yuan.

2. Use a rope to measure the thickness of a tree, use the rope 1 2 around the tree for 4 weeks and leave 1 5 meters, use the rope 1 3 around the tree for 2 weeks and 4 3 meters, what is the length of the rope and the circumference of the tree?

Answer] The rope is 4 1 2 8 times more than the circumference of the tree, 1 5 1 2 2 5 meters; It is 4 3 1 3 4 meters longer than 2 1 3 6 times longer than the tree. The circumference of the tree is (4 2 5) (8 6) meters, and the length of the rope is meters.

One ticket, each b yuan: (b-3)*3 2*a=6 5*a*b b=12 yuan;

2.The length of the rope a, the circumference of the tree b: 1 2a = 4b + 1 5 1 3a-4 3 = 2b a = b=

1. Set up A tickets, each B yuan. (a-3)*2b=a*b*(1+1/5)

Get: b = yuan.

1. Solution: Set the original price of a yuan per ticket, the audience has a total of b people, and the income is c yuan.

Columnar. a*b=c

a-3)*b(1+1 2)=c(1+1 5).

Divide two by one.

5（a-3）=4a

A=15A: The original price is 15 yuan per ticket.

2. Solution: Let the length of the rope be x meters and the circumference of the tree be y meters.

1/2x=4y+1/5

1/3x=2y+4/3

Finishing two styles. x=74/5 y=9/5

A: The length of the rope is 74 5 meters, and the circumference of the tree is 9 5 meters.

There is a formula for this problem: (first term, last term) number of terms: 2, so 2+4+6+8+10+...96+98+100=2+100+（4+98）+（8+96）+.50+52）=102×50÷2

Add that this has a total of 50 numbers, and +96....50+52 adds a total of 50 2 to 102, so you get 102 50 2

It's very simple, 1 to 100 is equal to 5050, and even numbers are more than the previous odd number, and there are 50 even numbers in 1,100, so (5050-50) 2=2500

If you look at the direction of the arrow, take one from both sides to the middle side, and finally divide the 50 numbers into 25 groups, I think.

1-100 is a total of 100 numbers, all are even numbers, 100 2=50 pairs.

Half find the middle, 100, half 50, 50+52

That is, how many even numbers are from 2 to 50, which is 50 2 = 25 pairs.

Mention 2 times and obviously 2 times (1+2+......50）

First: For example, 2--10, there are several, 5 is, it is even, 12--20 is also 5, a total of 50 numbers, except for 50, 100, a total of 24 pairs. 2 Second, this problem is not solved in this way, it should be 2+, 6+94....

50,100 plus that, for reference,

Because 2 100 has 50 even numbers, there are 25 pairs in total.

Do you have to be 2+100=102 and 4+98=102? Wouldn't you be 2+98=100, 4=96=100? 2 to 100 won't be counted, you won't be 2 to 10. And then don't you just make the value again? It's stupid.

Use the same equation 1Sum = (first term + last term) * number of terms 2 2Number of items = (last term - first term) Tolerance +1 Solution to this problem:

100-2) 2+1=50 (number of terms) (100+2)*50 2=2500

Out of 100 numbers, 50 are even and 50 are odd.

Half of 50, i.e. 25 102

The Mathematics Q&A team will answer for you, I hope it will be helpful to you.

24-16) ( = 160 points.)

The average monthly call is 160 minutes when choosing both types of cards charges as much.

When the average monthly call is less than 160 minutes, it is more appropriate to choose the B type charge, I wish you good progress in your studies and to the next level! (

Solution: Let x share the same number of two types.

24 Ten ten.

x=160Answer: When 160 points, the two costs are the same. If the score is less than 160, choose B.

4-1 3 (number of intervals).

6 3 2 seconds (every few seconds).

12-1 11 (number of intervals).

11 2 22 seconds (total time).

The ** of a bag of rice is 2 times that of a bottle of milk, which is equivalent to the money of buying a bag of rice to buy 2 bottles of milk, so the ** of each bottle of milk = 100 (2+3).

100 5 = 20 (yuan).

Then the rice of ** = 20 2 = 40 (yuan).