What number should replace the question mark? Seven sectors of a circle hold, in clockwise order from the top: 1, 4, 10, 19, 31, ?, 64. Answer with a natural number.
To which hexagon below can a dot be added so that it then meets the same conditions as in the hexagon above? Choose from the options labelled in the figure.
A greengrocer found that 68 tomatoes in a box were mouldy, which was 16 per cent of the total contents of the box. How many tomatoes were in the box? Answer with a natural number.
What number should replace the question mark? Three circles each have a top number and two lower numbers: 52 with 21 and 27; 34 with 22 and 44; 16 with 71 and ?. Answer with a natural number.