1000, 1020, 1040, 1060, 1080, and 1100
2100
1001, 1012, 1023, 1034, 1045, 1056, 1067, 1078, 1089, 1100
Oh, dude, let me put on my math hat for a sec. So, to find a number between 1100 and 1200 that's divisible by 11 and 13, we need to find the least common multiple of 11 and 13, which is 143. Then we just need to find which multiple of 143 falls within the given range. So, the number you're looking for is 1147. Boom, mathed it!
I write them exactly as they appear in the question.
1000, 1020, 1040, 1060, 1080, and 1100
The number is 1,144.
It is: 1144
The answer between 1 and 1000 is 840, but what about 1 and 1100?
1,001 1,012 1,023 1,034 1,045 1,056 1,067 1,078 1,089
1100
Two: 1020 and 1080.
2100
Just one possibility.... 1001
1001, 1012, 1023, 1034, 1045, 1056, 1067, 1078, 1089, 1100
1,100
342 = 1156 which is between 1100 and 1200 and is certainly a square number.