Peter must deliver a parcel from his company to his manager’s home by a scheduled time. At 40 km/h he would arrive 40 minutes early; at 30 km/h he would arrive 30 minutes late. How far is the journey?
Alex has a solid made from four rectangular prisms as shown. Each small prism shares a face with another. Three indicated faces have areas 6 cm², 15 cm² and 35 cm². What is the area of face x?
Circle C and square S have equal areas. Square S′ is inscribed in C, and circle C′ is inscribed in S. What is the ratio of the area of S′ to that of C′?
Jenny fills a 3×3 grid so that the sums in all four 2×2 subgrids are equal. Three corner entries are shown. What number must be put in the remaining corner?
An airline gives the same free checked-baggage allowance for every ticket and charges proportionally for excess weight. Mr and Mrs Brown check a combined 60 kg and pay 11 dollars extra. Mr Robin also checks 60 kg but pays 33 dollars extra. The Browns have twice Robin’s free allowance because they have two tickets. What is the free allowance per passenger, in kilograms?
Three kangaroos have pairwise distinct positive integer weights in kilograms, totalling 100 kg. Kanga is the lightest. What is Kanga’s largest possible weight?
Alice builds a large cube from n³ identical unit cubes, where n is an integer greater than 3. In general, how many unit cubes can be seen from outside the large cube?