Maths quiz answers
In a 7-digit numerical code each group of four adjacent digits adds to 16 and each group of five adjacent digits adds to 19. What is the sum of all seven digits?
Answer: 25 (The code would be 3337333)
The list 2,1; 3,2; 2,3; 1,4 ; describes itself, since there are two 1s, three 2s, two 3s and one 4. There is exactly one other list of eight numbers containing only the numbers 1, 2, 3, and 4 that, in the same way, describes the numbers of 1s, 2s, 3s and 4s in that order. What is the total number of 1s and 3s in this list?
Answer: 6 (The list would be 3,1; 1,2; 3,3; 1,4 )