What does this rebus mean?

O
N
C
E
TIME

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

Three brothers Jacob, John, and James live in Mexico City. The product of the ages of these brothers is 175. Jacob and John are twins. How old is James?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?

You see me once in June, twice in November, and not at all in May. What am I?

Can you find the next number in the sequence?

113 119 101 114 116 ?

Jim and Sarah are in a long-distance relationship. Jim buys an engagement ring for Sarah and wants to mail it to her. Unfortunately, the only way to ensure the ring will be received is to place a lock on the package. Jim has locks and Sarah has locks, but neither has keys for each other’s locks. How can they make sure the ring isn’t stolen?