391. What is the next number in this series?

21, 20, 18, 15, 11, ________?

6. Subtract one from the first number to get the second number, then 2 from the second number to get the third number, then 3 from the third number to get the fourth, etc.

392. What is represented by the wacky word?

lookbebebebeuleap

393. Can you complete this grid of letters. Each line is a valid 5 letter word
with its first and last letter missing. The missing letters form a word when read downwards and the same word appears both at the start and at the end. What
is the missing word?

?AGL?

?ABE?

?LUR?

?UTD?

?IDO?

ELBOW is the missing word.

394. There are two bars of iron. One bar is magnetized along its length, while the
other is not magnetized. Using just the two bars, without any other items, how can you tell which bar is magnetized and which is not?

Place the two magnets in the form of the letter T. Let A be the vertical magnet in the T, and B be the horizontal magnet in the T. Since a bar magnet has no magnetic effect at the middle, if B is the magnet, then A and B would not attract each other in this configuration. If A was the magnet, then its magnetic effect would be the strongest at the end and it would attract B.

395. If a crab and a half weigh a pound and a half, but the half crab weighs half
as much again as the whole crab, what do half the whole crab and the whole of the half crab weigh?

2.1 pounds. The whole crab must weigh 0.6 pounds, and the half crab 0.9 pounds, totaling 1 1/2 pounds. If the former were halved and the latter doubled, the weights would then be 0.3 and 1.8 pounds, totaling 2.1 pounds.

396. A man was telling me on a particular occasion, "The day before yesterday
I was 35 years old and next year I will turn 38." How can this be?

The man's birthday is December 31 and he was talking on January 1. He is 36 now, the day before yesterday he was 35, this calendar year he will turn 37, and next calendar year he will turn 38.

397. Using the numbers 1, 9, 9 and 9, in that order,
make the number 89. You may use brackets and any standard math operation such as the square root, +, -, * and /. For example, 26 = -1 + 9 + 9 + 9.

398. When you say my name, I no longer exist. What am I?

399. What is the number which is 4 times the number that is one-eighth of
one-tenth of one-half of 640

16. (640 ÷ 2 = 320 ÷ 10 = 32 ÷ 8 = 4 X 4 = 16).

400. What is represented by this wacky word?

VESTIPRIVATEGATOR

Private Investigator; [private IN vestigator].

401. Which is larger, the number of seconds in a day or the number hours in 10
years?

Hours in 10 years. There are 86,400 seconds in a day and there are over 87,000 hours in 10 years - including leap years.

402. What number is two-thirds of one-half of one-fourth of 240?

403. A recycling factory makes its own paper cups for
canteen use. It can make one new cup from nine used ones. If it has 515 used cups how many can it possibly make in total?

The maximum possible is 63.

404. A truck became wedged under a low bridge. It could not move forward or
back without severely damaging its roof. The truck driver was perplexed until a little girl standing nearby suggested an easy solution. What was it?

The little girl suggested that the driver let out enough air from the trucks tires to allow it to pass under the bridge.

405. Two clocks were correct at midnight but then one began
to gain four minutes every hour. It stopped one and a half hours ago showing 4:48 pm. The clocks run for less than 24 hours. What time will the other clock be showing?