30
A + B + C + D = 27
C = 3A
C is a single digit, and must be a multiple of three, so it has to be one of the numbers:
3, 6, 9
Let's start with our highest possibillity:
If A = 3, C = 9
B + D = 27 - (3 + 9)
B + D = 27 - 12 = 15
B = 8, D = 7 OR B = 7, D = 8
The number then can be 3897 or 3798
Now let's try a smaller value for A and C:
if A = 2, C = 6:
B + D = 27 - (2 + 6)
B + D = 19
But that can't be, because B + D are both single digits, and there are no two single digit numbers that add up to 19. The same will be true if A = 1, so the two combinations given above are the only ones.
3.14
3.1415926535897932384
They are: 3.1415926
The next number would be septillion
The first 20 digets after the dot in pi are: 3.14159265358979323846
Digits are numbers.
156
I dot ow is thhe prolem
40,000
3.14
3.1415926535897932384
They are: 3.1415926
4 and 7.
Zero
Triple digets
16001
It is so simple. The answer is 9.