Math Riddles

Question: what are the next two letters in this sequence: A, E, F, H, I, K, L, M,

Question: What are the next two letters in the following series and why? WATNTLITFS__

Question: When I was 2 years old, my brother was half my age. Now I am 100 years old, how old is my brother?

Question: When is... 5>0, 0>2 and 2>5? Hint: Hands

Question: Mary's father has three kids one is Alexis the second one is jolly who's the third?