If two days before yesterday was Thursday, how many more days from today will it be until Wednesday? (For example, Monday to Wednesday is 2 more days.)
A boat travels downstream from A to B in 2 hours and upstream from B to A in 4 hours. How many hours does a patch of floating plants take to drift from A to B?
The figure shows 16 circles arranged in a square, with 12 black circles along the outside border. If 196 circles are arranged in the same way, how many black circles are on the outside border?
Two kinds of square tiles, of side lengths 2 m and 3 m, cover a floor of area 492 square metres. Exactly 98 tiles are used and none is cut. How many of the 2 m tiles are used?
Use each digit 2, 3, 4, 5, 6, 7 and 8 exactly once. The different letters $U,V,W,X,Y,M,N$ stand for these different digits. Find the minimum value of $\overline{UVW}-(\overline{XY}+\overline{MN})$.
Bình has a box of cards bearing numbers. Châu removes one card, and Bình says that the average of the remaining numbers is 2 less than before. Châu removes one more card, and the average of the remaining numbers returns to the original average. The difference between the numbers on the two removed cards is 64. How many cards were originally in the box?
A teacher tells the class, “At least four of you have the same birth month.” What is the smallest class size that guarantees the teacher’s statement is true?
In the cryptarithm $I\times\overline{LOVE}=\overline{VTMO}$, different letters represent different digits and $O=0$. What is the largest possible value of $\overline{VTMO}$?
Replace different letters by different digits so that the sum $\overline{VIETNAM}+\overline{TITAN}+\overline{MATH}$ is as large as possible. Find $T+I+T+A+N$.
Two numbers form a “2022 pair” if both have four digits, one is divisible by 5 and the other by 6, and their difference is 2022. How many different such pairs are there? The pairs (a,b) and (b,a) count as the same pair.
Two squares overlap as shown. Their side lengths are natural numbers, but are not consecutive natural numbers. Region A has area 39 square centimetres more than region B. What is the area of the larger square, in square centimetres?
Dũng’s father packs apples into small and large boxes for sale. Either 10 small boxes and 8 large boxes, or 5 small boxes and 10 large boxes, hold exactly all the apples. If he uses only small boxes, how many boxes are needed to hold exactly all the apples?