Xiaofang is 5 years old this year. Three years later, teacher Li in Xiaofang kindergarten is 20 years older than Xiaofang. How old is teacher Li this year?

20 + 5 = 25 years old; a: Mr. Li is 25 years old

Xiao Li and Xiao Hua ran the 200 meter race. Xiao Li scored 3 / 2 points and Xiao Hua 12 / 7 points. Who can run fast?

3 / 2 = 21 / 14, 12 / 7 = 24 / 14, so Xiaohua spends a lot of time, that is, Xiaoli is fast

It took Xiaodong 18 seconds and Xiaoming 14 minutes to run 100 meters. Who can run fast?

Because 1 minute = 60 seconds, 1 second = 160 minutes, so 18 seconds = 18 × 160 = 310; 14 = 1 × 54 × 5 = 520, 310 = 3 × 210 × 2 & nbsp; = 620, because 620 > 520, that is 18 seconds > 14 minutes, Xiaoming runs fast

Xiao Ming used 48 yuan to buy six pencils and six pens. The money for two pens is exactly the same as that for six pencils. How much for each pen and pencil

Let X Yuan for pen and Y yuan for pencil be 6x + 6y = 482x = 6y. The solution is: x = 6y = 2. Answer: 6 yuan for pen and 2 yuan for pencil

Use 43 yuan to buy 5 pens and 6 pencils. A pen costs 5.3 yuan more than a pencil. How much is the unit price of each pen and pencil?
Elder brother and elder sister, please help me. I just learned, but I don't understand. Can you draw a picture or be more detailed? The result must be detailed

You can buy 5 pens and 6 pencils for 43 yuan. Pens are 5.3 yuan more expensive than pencils. It's OK to change all pens into pencils
43 yuan = 5 * 5.3 yuan + 5 pencils + 6 pencils
43 yuan = 26.5 yuan + 11 pencils
A pencil is 1.5 yuan
The pen is 1.5 + 5.3 = 6.8 yuan

1. Six pencils and one pen are 18 yuan in total. The unit price of pen is three times that of pencil. What are the unit prices of pen and pencil

Let pen be y, pencil be x 1.6x + y = 18, y = 3x and substitute x = 3.91, y = 11.73

Xiao Ming bought three pencils and two pens. The unit price of the pens is three times that of the pencils. The money Xiao Ming bought for these two pens is equivalent to the money he bought for () steel pens, as well as the money he bought for () steel pens
The sum of the subtracted, subtracted and difference is 1.04, and the subtracted is ()

Xiao Ming bought three pencils and two pens. The unit price of the pens is three times that of the pencils. Xiao Ming's money for these two pens is equivalent to the money for (3) steel pens and (9) pencils. The sum of the subtracted, subtracted and difference is 1.04, and the subtracted is (0.52)

Each pen costs 5 yuan, each ballpoint pen costs 3 yuan, and each pencil costs 1 yuan and 3 yuan. With 15 yuan to buy three kinds of pens, how many different ways can you think of?

One pen, one ballpoint pen, 21 pencils
One pen, two ballpoint pens, 12 pencils
One pen, three ballpoint pens and three pencils
Two pens, one ballpoint pen and six pencils

There are 28 boxes of pens and pencils, 300 pens in total. There are 10 pens in each box and 12 pencils in each box. How many pens are there in each of the two kinds of pens
Come on The equation!
In the process of writing equations, we need to set X

Suppose the pen has x box, then the pencil (28-x) has box
10x+12（28-x)=300
10x+336-12x=300
2x=36
x=18
A: there are 18 pens and 10 pencils

Xiao Ming took 31 yuan to buy the following three kinds of pens: ballpoint pen (2 yuan per pen), pencil (1 yuan per pen) and pen (5 yuan per pen)

If you want to buy more, of course, choose the cheaper to buy more and the more expensive to buy less
Therefore, the most buy method, buy a ballpoint pen and pen, the rest buy pencils
31-2-1 = 28.28 pencils, 1 ballpoint pen and 1 pen
The least way to buy is to buy a pencil, a ball point pen, and the remaining pens (if there is a surplus, try to buy expensive ones as much as possible)
31-2-1 = 28, 28 / 5 = 5, more than 3
3 yuan to buy 2 yuan ballpoint pen, 3 / 2 = 1 more than 1, the balance to buy a pencil
Therefore, the least way to buy is to buy 5 pens, 2 ballpoint pens and 2 pencils

Xiaofang is 5 years old this year. Three years later, teacher Li in Xiaofang kindergarten is 20 years older than Xiaofang. How old is teacher Li this year?