Suppose the number, when written is XY.
Then sum of digits = 10 implies that X+Y = 10
Also, 20 < XY < 32 implies that X = 2 or 3.
Suppose X = 3
Then X+Y = 10 requires Y = 7. But that is not possible because the number cannot be greater than 32.
So, X must be 2.
And then, X+Y = 10 implies that Y = 8 and so the number is 28.
28
The sum of the number of digits in all the numbers between 31 and 400 inclusive is 1041.
The answer is 28
This cannot be answered. This will have to be written to where it can be understood.
20 number
28
The number is: 36725918 In descending order that is: 98765321 The pairs of numbers that have as many digits between them in both are: 3,9 5,8 6,7 So there are three pairs.
The sum of the number of digits in all the numbers between 31 and 400 inclusive is 1041.
Digits is how many numbers you have in a number. If you have the number 4 it has one digit if you have the number 20 it has two digits and if you have the number 558 it has three digits. So basically in the number 1085 it has 4 digits because there is 4 numbers in it, the numbers are 1,0,8 and 5. Hoped you understand.
The answer is 28
This cannot be answered. This will have to be written to where it can be understood.
When multiplying numbers with significant digits, count the total number of significant digits in each number. Multiply the numbers as usual, but round the final answer to match the least number of significant digits in the original numbers.
20 number
That is a trick question. 10 is the same number as 10.000, it is merely expressed with fewer significant digits. There are no numbers between one number and itself.
When multiplying numbers with significant digits, count the total number of significant digits in each number being multiplied. The result should have the same number of significant digits as the number with the fewest significant digits. Round the final answer to that number of significant digits.
Armstrong numbers are the sum of their own digits to the power of the number of digits.
roman numbers............