A can give B 40 m and C 82 m in a 880 m race while B can give C 9 seconds over the post, find the time C takes to run 880 m.

If A runs 880 meter then B runs 840 meters and C runs 798 meters.
∵ B runs 840 m while C 798 m
∴ B runs 880 m while C 798 * 880 / 840 = 836 m
Now, 880 – 836 = 44 m
Hence, C runs 44 m in 9 seconds
∴ C runs 880 m in 9 * 880 / 44 = 180 sec. = 3 min.