84
U={whole number greater than 10 but smaller than 30 } X={numbers divisible by 3 } Y Odd numbers
56 of them.
If the sum of its' digits are divisible by 3 for all numbers greater than 9.
Three of them.
84
U={whole number greater than 10 but smaller than 30 } X={numbers divisible by 3 } Y Odd numbers
They are all the numbers divisible by 2 with no remainder
56 of them.
If the sum of its' digits are divisible by 3 for all numbers greater than 9.
78,84,90,96
Three of them.
49
49
There are multiple numbers which meet this criteria. 71,73,74,75,77,78,79,81,82,83,85,86,87,89,91,93,94,95,97,98 & 99.
300.000000000000000000000000000000000000000000000 etc ... 00001 is divisible by 9. Whole numbers with no remainder. 306.
NO, it is not divisible by all numbers. This is easy to see if you remember that 27 is an odd number and odd numbers are NOT divisible by 2. Then there is the issue that is is NOT divisible by any number greater than itself. That is a lots of numbers that don't work!