Use VB to calculate the number between 100 and 999 whose single digit is 3 and can be divided by 7 and output

Use VB to calculate the number between 100 and 999 whose single digit is 3 and can be divided by 7 and output

For i = 100 To 999
If i Mod 10 = 3 And i Mod 7 = 0 Then
Print i
End If
Next i

3 * 7 = 21 13 * 17 = 221 23 * 27 = 621

Let n be a nonnegative integer (10N + 3) * (10N + 7) = 100N & sup2; + 100N + 21 = 100 * n * (n + 1) + 21, with the same ten bits, and the sum of the ten bits is the product of two factors. For example, 72 * 78 = 5616 & n

By calculating 27 * 23 = 621, we find that 21 = 7 * 3 in the last two digits of the product, and 6 = 2 * (2 + 1) in front of it. If we replace it with two digits 84 * 86 = 7224, we also have such characteristics. So we guess that the product of the same ten digits and two two two digits with 10 has such rules. Can you explain the correctness of this conjecture?

Correct
Let the two double digits be 10N + A and 10N + B, and a + B = 10
Then,
(10n+a)(10n+b)
=100n²+10n×(a+b)+ab
=100n²+10n×10+ab
=100n(n+1)+ab

The head is the same and the tail is complementary (the tail sum equals 10 24 * 27 = (23 + 1) * 27 2 + 1 = 3 2 × 3 = 6 3 × 7 = 21 24 × 27 = 23 * 27 + 27 = 621 + 27 = 648)
How to calculate the next 25 * 27,

25x27
=25x(25+2)
=25x25+25x2 {2+1=3 2x3=6 5x5=25}
=625+50
=675
Or:
25x27
=(23+2)x27
=23x27+2x27 {2+1=3 2x3=6 3x7=21}
=621+54
=675

What are the maximum six digits that can be divisible by three, seven, eight and eleven at the same time______ ．

The least common multiple of 3, 7, 8, 11 is 1848. Because 999999 △ 1848 = 541 From the quotient and remainder, we can see that the maximum six digit number that meets the condition is 541 times of 1848, or the difference between 999999 and 231. Therefore, the six digit number that meets the condition is 999999-231 = 999768

79 / 90 23 / 42 4 / 9 23 / 40 which number is closer to 1 / 2

23/42

A 24-hour electronic watch displays from 00:00:00 to 23:59:59 in a day. Every moment has six digits. The moment when the first three digits are exactly the same as the last three digits is called "lucky moment". How many "lucky moments" are there in a day?

When the first number is 0,1, the second number is 0 ~ 5
When the first number is 2, the third number is 0 ~ 3
The third number is 0-5
Total: (2 * 6 + 4) * 6 = 96

There is a four digit number, and a decimal point is added after a certain digit. When it is added with the original number, 4004 will be obtained. What is the number? There must be a decimal point

3640 or 4000 are OK, add a decimal point after a certain number. The first case: it shows that the current number is the result of reducing the original number by 10 times. If the current number is regarded as one, the original number is 10, and the sum of the two numbers is (1 + 10) = 11, 4004 △ 11 = 364, then one (the existing number) can be obtained, and the original number = the current number

The sum of a three digit number plus the decimal point and the original number is 985.76. What is the three digit number

Decimals are two decimal places, reduced by 100 times
Three digit = 985.76 ÷ (1 + 0.01) = 976

How to calculate the circumference of a semicircle?

Area of semicircle = area of circle △ 2
Semicircle circumference = half of circumference + diameter