Use Chinese Remainder Theorem for (2),(3).

For (2), your a_1, a_2, a_3 in the above link are 2,3,6, respectively.

Your m_1, m_2, m_3 are 3,5,7 (relative primes).

Your M would be 3*5*7 = 105.

You need to calculate each b's value in the above link and calculate x (Verify your answer is correct).