Problem:
Suppose hops, skips and jumps are specific units of length. If b hops equals c skips, d jumps equals e hops, and f jumps equals g meters, then one meter equals how many skips?
Answer Choices:
A. cefbdg
B. begcdf
C. befcdg
D. bdgcef
E. bdfceg
Solution:
We are given
b hops =c skips, or 1 hop =bc skips; d jumps =e hops, or 1 jump =de hops; f jumps =g meters, or 1 meter =gf jumps.
Substituting repeatedly gives
1 meter =gf jumps =gf(de hops )=gf(de(bc skips ))=bdgcef skips.