Please answer this question: 3 digit number

1. by itself is not sufficient. If the units digit of the number k is 9, then you get that the tens digit of k+4 = tens digit of k +1, meaning 2. If the units digit of k is, let's say, 3, then the units digit of k and k+4 are equal, giving us the tens digit of 3.
2. by itself is sufficient. This is because the units digit of k is not zero. Since k + 9 has the same tens digit as k only if the units digit of k is zero, that means that the tens digit of k = (tens digit of k+4)-1, meaning 3.