Problem 1) correct
Problem 2) correct
Problem 3) incorrect; answer is 8
Problem 4) incorrect; answer is 3
Problem 5) correct
Problem 6) correct
Problem 7) incorrect; answer is 59
Problem 8) incorrect; answer is 99
Problem 9) correct
Problem 10) incorrect; answer is 25
Problem 11) correct
Problem 12) incorrect; answer is 76
88 = W
52 = I
8 = L
8 = L
3 = G
52 = I
70 = V
67 = E
59 = Y
99 = O
31 = U
25 = A
164 = R
52 = I
76 = N
3 = G
It decodes to "Will give you a ring" which has a double meaning. The first meaning is "I'll give you a wedding ring" and the second is "I'll give you a call" (which is British English)