30, 60 and 90.
lcm(2, 3, 5) = 30 → 2 digit common multiples are 30, 60, 90.
Use some method which you probably already learned, to find the least common multiple. All the other common multiples are multiples of this least common multiple, so you can multiply the least common multiple by 2, by 3, by 4, etc., to get additional common multiples.
All of the odd numbers between 11 and 99 inclusive are two digit numbers that are not multiples of 2. There are 45 of them.
12, 24, 36, 48, 60, 72, 84, and 96 are.
60 numbers
It's 52
the first two common multiples of 15,27 are 135,270
The first two common multiples of 235 is 5 and 47.
There are none.
45 multiples of 2 plus 30 multiples of 3 minus 15 multiples of 6 equals 60 numbers
2
A single number cannot have any common multiples - you need two or more numbers to compare.