Random Puzzles 

Workings

Hints
The first letters of the words are: T, T, H, D, W, L, H, W, C, N.

Answers
tel + esc + ope = telescope
tim + eta + ble = timetable
hai + rbr + ush = hairbrush
dif + fer + ent = different
wat + erf + all = waterfall
lig + htn + ing = lightning
hea + dli + ght = headlight
whi + rlw + ind = whirlwind
car + til + age = cartilage
new + sag + ent = newsagent

Workings

Hint
The answer involves months of the year.

Answer
6.

The number of letters each month has, starting with January, therefore, August has 6 letters.

Workings

Hint
Look at the tops of the towers.

Answer
Add the two lines to the second tower from the left to complete the 'X' in the inverted letter sequence U, V, W, X, Y forming the towers' roofs.

Workings

Hint
How many large pipes are required to drain the reservoir in 24 hours?

Answer
21 hours and 36 minutes.

Reasoning
Looking at the first clue:
   in 12 hours, 6 large pipes can drain 1 reservoir
   in 24 hours, 6 large pipes can drain 2 reservoirs
   in 24 hours, 3 large pipes can drain 1 reservoir (*)

Looking at the second clue:
   in 8 hours, 3 large + 9 small pipes can drain 1 reservoir
   in 24 hours, 3 large + 9 small pipes can drain 3 reservoirs

But, by (*), we know that in those 24 hours, 3 large pipes can drain 1 of those reservoirs.

Therefore, the other 2 reservoirs can be drained by the small pipes on their own:
   in 24 hours, 9 small pipes can drain 2 reservoirs
   in 24 hours, 1 small pipe can drain ²⁄₉ reservoirs

multiply the hours by 9:
   in 216 hours, 1 small pipe can drain 2 reservoirs
   in 216 hours, 5 small pipes can drain 10 reservoirs

divide the hours by 10:
   in 21.6 hours, 5 small pipes can drain 1 reservoir

21.6 hours = 21 hours and 36 minutes.