-1. Twice eight are ten of us, and ten but three.
Three of us are five. What can we be?
If this is not enough, I will tell you more.
Twelve of us are six, and nine but four.

-2. The result of adding the date of the last Monday of last month and the date of the first Thursday of next month is 38. If both dates are in the same year, what month is it?

-3. How many flowers do I have if all of them are roses except two, all of them are tulips except two, and all of them are daisies except two?

-4. Sir Worrier invited 14 other knights to a meal at the castle in Camelot. Before sitting down, each of the fifteen knights shook hands with each of the other knights.

How many handshakes occurred?

3. three, one of each flower

4: 105 ; n = number of people:
Formula: n(n-1)/2 = 15*14/2 = 105

people:handshakes
1:0 2:1 3:3 4:6 5:10 .........14:91 15:105

Take 5 shakers a,b,c,d,e:
ab,ac,ad,ae
bc,bd,be
cd,ce
de

Both correct!

1. letters in the number words

So sneaky!

2. August for the same year (31 + 7). It could be January if you cross over the years.

Spot on, Cue!

That one had me stumped for a while:
thought the months were consecutive!!