p, q and r are three
points on the real number line where q = (2pr)/(p+r).
Quantity A: mod(1/p
- 1/r)
Quantity B: mod(1/q
- 1/p)
Explanation:
q = (2pr)/(p+r)
qp + qr = 2pr
(1/r) + (1/p) = (2/q)
[(1/r) + (1/p)]/2 = (1/q)
Thus we see that (1/q) is
the arithmetic mean of (1/r) and (1/p).
Thus mod(1/p - 1/r)
will be greater than mod(1/q - 1/p).
Quantity A is greater.