Provide your best answer for the following math problem. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The problem is: in a 1000 m race , a beats b by 70 m and b beats c by 100 m . in the same race , by how many meters does a beat c ?
163 m
170 m.