19. The integers from 1 to $n$, inclusive, are equally spaced in order round a circle. The diameter through the position of the integer 7 also goes through the position of 23 , as shown. What is the value of $n$ ?
A 30
B 32
C 34
D 36
E 38
19. B Since the integer 7 is joined by a diameter to the integer 23 , we can deduce that there are $23-7+1=15$ integers between them on each side. Therefore there are $2 \times 15+2=32$ integers in total round the circle. Hence the value of $n$ is 32 .