🗝 Answer Key 

1. 1:01 (After 12:21, the hours cycle back to 1. The first palindrome in the 1 o'clock hour is 1:01).

2. 3 socks (If the first is blue and the second is black, the third must match one of them).

3. 4 times (The original area is 4 x 4 = 16. The new area is 8 x 8 = 64. 64 ÷ 16 = 4).

4. 10 handshakes (The first person shakes 4 hands, the second shakes 3 new hands, the third shakes 2, and the fourth shakes 1).

5. 55 (There are five pairs that all equal 11: 1+10, 2+9, 3+8, 4+7, 5+6. 5 times 11 = 55)