2.22 is asking to extend the Sieve of Eratosthenes to find primes up to 210. You'll need to eliminate some multiples of 2, 5, 3, etc. up to 13, which is the largest prime less than the square root of 210.

On 2.29, the numbers 418, 437 and 456 have one prime factor in common. To find it, it might be helpful to look at the difference of some pair of those numbers (if two numbers are divisible by a third, that third number also divides the difference).