A rabbit must reach the carrot without entering a rock cell or visiting any cell more than once. How many different routes are possible?
Reading convention: each step goes to an edge-adjacent cell, horizontally or vertically, never diagonally. This usual grid convention is made explicit here.
Robbie has two ropes of length 1 dm and two ropes of length 7 cm. He joins some of them end to end. Which listed length cannot be made? Ignore length lost at joins.
A bookstore records its black-pen and blue-pen sales over three days. The number of blue pens sold on day 3 is twice that on day 1. How many pens altogether are sold on day 1?
Black pen = Bút đen; Blue pen = Bút xanh; Day = Ngày; Total pens sold in 3 days = Tổng số bút bán trong 3 ngày.
Turtle and rabbit run a relay. Turtle starts at 07:15, runs half the route, and hands the baton to rabbit. Rabbit runs four times as fast and finishes at 07:35. When is the baton passed?
Grandma has a square piece of land of area 100 m². She sells a smaller square of area 25 m², removed from the interior of one side as shown. Find the remaining land’s perimeter.
The original image label “Granda’s land” names the same piece of land.
Peter has identical L-shaped pieces (figure A), each covering three small squares. He fits them inside figure B without overlap, allowing rotations. What is the least number of uncovered squares?
Eight planks make one goat pen as pictured. What is the minimum number of planks needed for four pens for four goats?
Intended construction model made explicit: four congruent square pens stand on one level in an edge-connected square-grid arrangement. A shared rail or corner post is used once. Each of the four rails and four upright posts shown counts as one plank.
Mr Smith reaches the airport at 10:35. His flight code contains a four-digit natural number divisible by 4, and his gate number is even. Using the original departure board, how many minutes must he wait?
Departures = Khởi hành; Time = Giờ; Flight = Chuyến bay; Destination = Điểm đến; Gate = Cổng. A four-digit natural number is at least 1000, so a leading-zero code is not one.
A firefighter starts on the middle step of a ladder, climbs up 6 steps, goes back down 10 steps, then climbs up 18 steps to reach the top step. How many steps does the ladder have?
Eight people, Amy, Bill, Cindy, Dan, Emma, Fred, Greg and Henry, meet. Among the other seven people, their friend counts are: Amy 7, Bill 6, Cindy 5, Dan 4, Emma 3, Fred 2, Greg 1. How many friends does Henry have? Friendship is mutual.