21,42,63,84
There are fourteen multiples of seven that are under 100.
14 of them.
Just 72.
It's 72
99
I don't know! Why are you asking me? Ask your teacher and He or she will tell you the answer!
To find prime numbers less than 100, the sieve of eratosthenes filters out 1 and all multiples of 2, 3, 5, and 7. All remaining numbers less than 100 are primes.
4,8,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68,72,76,80,84,88,92,96
21,42,63,84
There are ten different integral multiples of 10 that are equal or less than 100.
The multiples of 5 that are also multiples of 6 are multiples of their LCM. The LCM of 5 and 6 is 30, so the question becomes which multiples of 30 are less than 100? The solution is the numbers: 30, 60, 90
33