Question

If
a/b = 21/34;
b/c = 121/120;
c/d = 17/77;
e/f = 11/15
and
d/e = 14/17
then what is the value of
(abc/def)*2?

Answer 1

2*(abc/def) = 2*(a/d)(b/e)(c/f) = 2*(a/b * b/c * c/d)(b/c * c/d * d/e)(c/d * d/e * e/f)
= 2*(21/34 * 121/120 * 17/77)*(121/120 * 17/77 * 14/17)*(17/77 * 14/17 * 11/15) = 121/18000