The digits can be built from matchsticks as shown. Both 15 and 8 use seven matchsticks. What is the largest positive integer that can be built with exactly seven matchsticks?
Anna has five circular discs of different sizes. She builds a tower of four discs, each smaller than the disc immediately below it. How many different towers are possible?
Francesca writes three consecutive two-digit numbers in order, replacing digits with symbols: $\square\diamondsuit$, $\heartsuit\triangle$, $\heartsuit\square$. Which number comes next?
Maria, Peter, Richard and Tina broke a classroom window while playing football. Maria says, “It was Peter.” Peter says, “It was Richard.” Richard says, “It was not me.” Tina says, “It was not me.” Exactly one child tells the truth. Who broke it?
Lukas colours the five rectangles red, blue and yellow. Rectangles sharing a side segment must have different colours. How many colourings are possible?
Goran may take any top group of blocks and reverse its order, as illustrated. What is the smallest number of moves taking the initial stack to the target stack?
On the circular track, the beaver moves 1 space per move, the rabbit 2 and the kangaroo 3. All start at START and must land exactly on FINISH. Who uses the fewest complete moves?