(a) Simplify (n/k)/(n/(k - 1))
(b) For some positive integer n, the expansion of (1 + x)^n has three consecutive coefficients a, b, c that satisfy 1:8:28. What must n be?
\(\phantom{1:8:40}\)
The answer for (b) is 8, because 8 choose 0,1,2 are 1,8, and 28
What about 1:2:3? What about 2:3:4?
Other numbers:
2:5:7
10:11:12
13:14:15:
2:5:8
1:8:40
1:3:5
2:12:17
3:10:19
